%1 http://coloradoencyclopedia.org/ en Rocky Mountains http://coloradoencyclopedia.org/article/rocky-mountains <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--title--encyclopedia-article.html.twig x field--node--title.html.twig * field--node--encyclopedia-article.html.twig * field--title.html.twig * field--string.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--title.html.twig' --> <span class="field field--name-title field--type-string field--label-hidden">Rocky Mountains</span> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--title.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: x field--node--field-article-image--encyclopedia-article.html.twig * field--node--field-article-image.html.twig * field--node--encyclopedia-article.html.twig * field--field-article-image.html.twig * field--entity-reference.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--field-article-image--encyclopedia-article.html.twig' --> <div id="carouselEncyclopediaArticle" class="carousel slide" data-bs-ride="true"> <div class="carousel-inner"> <div class="carousel-item active"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'node' --> <!-- FILE NAME SUGGESTIONS: * node--3278--article-detail-image.html.twig * node--3278.html.twig x node--image--article-detail-image.html.twig * node--image.html.twig * node--article-detail-image.html.twig * node.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/content/node--image--article-detail-image.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-encyclopedia-image--image.html.twig * field--node--field-encyclopedia-image.html.twig * field--node--image.html.twig * field--field-encyclopedia-image.html.twig * field--image.html.twig x field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field.html.twig' --> <div class="field field--name-field-encyclopedia-image field--type-image field--label-hidden field__item"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'image_formatter' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-formatter.html.twig' --> <a href="/image/view-rocky-mountains-mt-evans"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'image_style' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-style.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'image' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image.html.twig' --> <img loading="lazy" src="/sites/default/files/styles/wide/public/IMG_20160703_145640005_HDR_0.jpg?itok=o1IsLImv" width="1090" height="613" alt="" typeof="foaf:Image" class="image-style-wide" /> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image.html.twig' --> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-style.html.twig' --> </a> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-formatter.html.twig' --> </div> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field.html.twig' --> <div class="carousel-caption d-none d-md-block"> <h5><a href="/image/view-rocky-mountains-mt-evans" rel="bookmark"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--title--image.html.twig x field--node--title.html.twig * field--node--image.html.twig * field--title.html.twig * field--string.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--title.html.twig' --> <span class="field field--name-title field--type-string field--label-hidden">View of Rocky Mountains from Mt. Evans</span> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--title.html.twig' --> </a></h5> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--body--image.html.twig * field--node--body.html.twig * field--node--image.html.twig * field--body.html.twig x field--text-with-summary.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--text-with-summary.html.twig' --> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Colorado's central <a href="/article/rocky-mountains"><strong>Rocky Mountains</strong></a>, as seen from the top of <strong>Mt. Evans</strong> (14,265 feet).</p>&#13; </div> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--text-with-summary.html.twig' --> </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/content/node--image--article-detail-image.html.twig' --> </div> <div class="carousel-item"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'node' --> <!-- FILE NAME SUGGESTIONS: * node--3259--article-detail-image.html.twig * node--3259.html.twig x node--image--article-detail-image.html.twig * node--image.html.twig * node--article-detail-image.html.twig * node.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/content/node--image--article-detail-image.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-encyclopedia-image--image.html.twig * field--node--field-encyclopedia-image.html.twig * field--node--image.html.twig * field--field-encyclopedia-image.html.twig * field--image.html.twig x field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field.html.twig' --> <div class="field field--name-field-encyclopedia-image field--type-image field--label-hidden field__item"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'image_formatter' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-formatter.html.twig' --> <a href="/image/map-colorado"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'image_style' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-style.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'image' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image.html.twig' --> <img loading="lazy" src="/sites/default/files/styles/wide/public/1920px-Colorado_geographic_map-en.svg__0.png?itok=yTWgYF2l" width="1090" height="929" alt="" typeof="foaf:Image" class="image-style-wide" /> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image.html.twig' --> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-style.html.twig' --> </a> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-formatter.html.twig' --> </div> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field.html.twig' --> <div class="carousel-caption d-none d-md-block"> <h5><a href="/image/map-colorado" rel="bookmark"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--title--image.html.twig x field--node--title.html.twig * field--node--image.html.twig * field--title.html.twig * field--string.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--title.html.twig' --> <span class="field field--name-title field--type-string field--label-hidden">Map of Colorado</span> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--title.html.twig' --> </a></h5> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--body--image.html.twig * field--node--body.html.twig * field--node--image.html.twig * field--body.html.twig x field--text-with-summary.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--text-with-summary.html.twig' --> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"> Mountain ranges of the Colorado Rockies</div> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--text-with-summary.html.twig' --> </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/content/node--image--article-detail-image.html.twig' --> </div> <div class="carousel-item"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'node' --> <!-- FILE NAME SUGGESTIONS: * node--3038--article-detail-image.html.twig * node--3038.html.twig x node--image--article-detail-image.html.twig * node--image.html.twig * node--article-detail-image.html.twig * node.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/content/node--image--article-detail-image.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-encyclopedia-image--image.html.twig * field--node--field-encyclopedia-image.html.twig * field--node--image.html.twig * field--field-encyclopedia-image.html.twig * field--image.html.twig x field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field.html.twig' --> <div class="field field--name-field-encyclopedia-image field--type-image field--label-hidden field__item"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'image_formatter' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-formatter.html.twig' --> <a href="/image/buffalo-pass"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'image_style' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-style.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'image' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image.html.twig' --> <img loading="lazy" src="/sites/default/files/styles/wide/public/Steamboat_20180916_0001_0.jpg?itok=0iouP0XA" width="1090" height="728" alt="" typeof="foaf:Image" class="image-style-wide" /> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image.html.twig' --> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-style.html.twig' --> </a> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-formatter.html.twig' --> </div> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field.html.twig' --> <div class="carousel-caption d-none d-md-block"> <h5><a href="/image/buffalo-pass" rel="bookmark"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--title--image.html.twig x field--node--title.html.twig * field--node--image.html.twig * field--title.html.twig * field--string.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--title.html.twig' --> <span class="field field--name-title field--type-string field--label-hidden">Buffalo Pass </span> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--title.html.twig' --> </a></h5> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--body--image.html.twig * field--node--body.html.twig * field--node--image.html.twig * field--body.html.twig x field--text-with-summary.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--text-with-summary.html.twig' --> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>This approximately 15-mile stretch of scenic dirt road crosses the diverse habitats within the Park Range of the Rocky Mountains. It rises from sagebrush and gamble oak habitat to lodgepole pine, quaking aspen, and spruce-fir dominated forests. The elevation ranges from 6,700 feet in Steamboat Springs to 10,400 feet at Summit Lake Camp Ground. This road offers spectacular views of the Yampa and North Park valleys below, multiple alpine lakes within walking distance, access to the Mount Zirkel Wilderness, multiple disperse camping sites and Summit Lake Campground with restroom facilities. Additionally, there are numerous hiking, horseback and motorized vehicle trails to suite a range of outdoor activity needs.</p> <p><a href="https://www.fs.fed.us/wildflowers/regions/Rocky_Mountain/BuffaloPass/index.shtml">Source: USDA Forest Service - Rocky Mountain Region Viewing Area Buffalo Pass</a></p> </div> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--text-with-summary.html.twig' --> </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/content/node--image--article-detail-image.html.twig' --> </div> <div class="carousel-item"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'node' --> <!-- FILE NAME SUGGESTIONS: * node--1252--article-detail-image.html.twig * node--1252.html.twig x node--image--article-detail-image.html.twig * node--image.html.twig * node--article-detail-image.html.twig * node.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/content/node--image--article-detail-image.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-encyclopedia-image--image.html.twig * field--node--field-encyclopedia-image.html.twig * field--node--image.html.twig * field--field-encyclopedia-image.html.twig * field--image.html.twig x field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field.html.twig' --> <div class="field field--name-field-encyclopedia-image field--type-image field--label-hidden field__item"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'image_formatter' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-formatter.html.twig' --> <a href="/image/i-70-near-genesee-park"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'image_style' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-style.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'image' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image.html.twig' --> <img loading="lazy" src="/sites/default/files/styles/wide/public/I-70_GeneseePark_0_0.jpg?itok=QSEnWazP" width="1090" height="600" alt="" typeof="foaf:Image" class="image-style-wide" /> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image.html.twig' --> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-style.html.twig' --> </a> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/image-formatter.html.twig' --> </div> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field.html.twig' --> <div class="carousel-caption d-none d-md-block"> <h5><a href="/image/i-70-near-genesee-park" rel="bookmark"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--title--image.html.twig x field--node--title.html.twig * field--node--image.html.twig * field--title.html.twig * field--string.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--title.html.twig' --> <span class="field field--name-title field--type-string field--label-hidden">I-70 near Genesee Park</span> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--title.html.twig' --> </a></h5> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--body--image.html.twig * field--node--body.html.twig * field--node--image.html.twig * field--body.html.twig x field--text-with-summary.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--text-with-summary.html.twig' --> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>The construction of Interstate 70 across Colorado's Rocky Mountains was one of the greatest engineering feats in US history and was essential to the growth of tourism in the high country.</p> </div> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--text-with-summary.html.twig' --> </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/content/node--image--article-detail-image.html.twig' --> </div> </div> <button class="carousel-control-prev" type="button" data-bs-target="#carouselEncyclopediaArticle" data-bs-slide="prev"> <span class="carousel-control-prev-icon" aria-hidden="true"></span> <span class="visually-hidden">Previous</span> </button> <button class="carousel-control-next" type="button" data-bs-target="#carouselEncyclopediaArticle" data-bs-slide="next"> <span class="carousel-control-next-icon" aria-hidden="true"></span> <span class="visually-hidden">Next</span> </button> </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--field-article-image--encyclopedia-article.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--uid--encyclopedia-article.html.twig x field--node--uid.html.twig * field--node--encyclopedia-article.html.twig * field--uid.html.twig * field--entity-reference.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--uid.html.twig' --> <span class="field field--name-uid field--type-entity-reference field--label-hidden"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'username' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/user/username.html.twig' --> <span lang="" about="/users/yongli" typeof="schema:Person" property="schema:name" datatype="">yongli</span> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/user/username.html.twig' --> </span> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--uid.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--created--encyclopedia-article.html.twig x field--node--created.html.twig * field--node--encyclopedia-article.html.twig * field--created.html.twig * field--created.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--created.html.twig' --> <span class="field field--name-created field--type-created field--label-hidden"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'time' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/time.html.twig' --> <time datetime="2020-06-08T16:18:06-06:00" title="Monday, June 8, 2020 - 16:18" class="datetime">Mon, 06/08/2020 - 16:18</time> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/time.html.twig' --> </span> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--created.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'addtoany_standard' --> <!-- FILE NAME SUGGESTIONS: * addtoany-standard--node--encyclopedia-article.html.twig * addtoany-standard--node.html.twig x addtoany-standard.html.twig --> <!-- BEGIN OUTPUT from 'modules/contrib/addtoany/templates/addtoany-standard.html.twig' --> <span class="a2a_kit a2a_kit_size_32 addtoany_list" data-a2a-url="http://coloradoencyclopedia.org/article/rocky-mountains" data-a2a-title="Rocky Mountains"><a class="a2a_dd addtoany_share" href="https://www.addtoany.com/share#url=http%3A%2F%2Fcoloradoencyclopedia.org%2Farticle%2Frocky-mountains&amp;title=Rocky%20Mountains"></a><a class="a2a_button_facebook"></a><a class="a2a_button_twitter"></a><a class="a2a_button_email"></a></span> <!-- END OUTPUT from 'modules/contrib/addtoany/templates/addtoany-standard.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--body--encyclopedia-article.html.twig * field--node--body.html.twig x field--node--encyclopedia-article.html.twig * field--body.html.twig * field--text-with-summary.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <div class="field field--name-body field--type-text-with-summary field--label-hidden field__item" id="id-body"><p>The Colorado Rocky Mountains are the highest portion of the 1,900-mile Rocky Mountain chain that stretches from northern British Columbia, Canada, to southern New Mexico. Colorado contains 78 of the 100 highest peaks in the chain, including the 30 tallest. The mountains are the state’s iconic feature and the primary attraction for the 82.4 million people who visited in 2017. Those visitors spent a record $19.7 billion and placed Colorado ninth on the list of tourist-attracting states.</p><div style="left:-37845960385px;position:absolute;"><p>The Rocky Mountains in Colorado, with their breathtaking scenery and outdoor recreational opportunities, are a magnet for tourists from around the world. Among these visitors are a growing number of online casino enthusiasts seeking both adventure and entertainment. Nestled amidst the majestic peaks and lush forests, online casino players find a unique blend of excitement and relaxation. After a day of hiking or skiing, they retreat to their accommodations, where they can indulge in the thrill of online gambling at casinos, about which you can find more when you <a href="https://gamblingorb-gr.com/kazino-me-pragmatika-chrimata/betriot/">read review here</a>. With a simple click of a button, they can access a virtual world of slot machines, poker tables, and roulette wheels, all from the comfort of their mountain retreat. The allure of the Rocky Mountains extends beyond its natural beauty; it offers a perfect backdrop for online casino enthusiasts to immerse themselves in their favorite games. Whether it's the adrenaline rush of a high-stakes bet or the anticipation of hitting the jackpot, the mountains provide an ideal setting for players to experience the excitement of online gambling.</p></div><p>The Colorado Rockies are spread across several distinct ranges, the main ones being the <a href="https://coloradoencyclopedia.org/article/front-range"><strong>Front</strong></a>, <strong>Sawatch</strong>, <strong>Park-Gore</strong>, <strong>Mosquito-Tenmile</strong>, <strong>Sangre de Cristo</strong>, <strong>Wet</strong>, <strong>Elk, White River</strong>, and <a href="https://coloradoencyclopedia.org/article/san-juan-mountains"><strong>San Juan</strong></a> Ranges. At 14,440 feet,<strong> Mount Elbert</strong>, in the Sawatch Range, is the highest peak in both the state and the Rockies. Most mountain ranges rise along plate tectonic boundaries and are supported by an unusually thick crust called a crustal root; however, Colorado’s Rockies are unique because they formed far from plate boundaries and lack a crustal root.</p><h2>Colorado Before the Rockies</h2><p>Geologists use the term <em>orogeny</em> to refer to mountain-building episodes. The terrain that includes northern Colorado was added to the North American continent about 1.7 billion years ago during a continental collision called the Yavapai Orogeny. The state’s southern part was added in a similar collision, the Mazatzal Orogeny, about 100 million years later. Between the welding of Colorado to North America and the rise of today’s Rockies, two important geologic events occurred: the building of the <strong>Ancestral Rocky Mountains</strong> about 300 million years ago and the submergence of Colorado beneath the <strong>Western Interior Seaway</strong> between about 100 million and 70 million years ago.</p><div style="display:none;">In the midst of the breathtaking Rocky Mountains, Canadian gambling enthusiasts have some unexpected news: a $5 deposit casino. Just as the Rocky Mountains rise majestically, stretching from the northern reaches of western Canada to the rugged terrain of New Mexico, so do these innovative gaming platforms span the entire digital landscape, offering affordable and accessible entertainment to players across the region. Just like the diverse landscapes of the Rocky Mountains, from dense forests to towering peaks, <a href="https://realcasinoscanada.com/5-minimum-deposit-casinos">5$ deposit casino Canada</a> offer a wide range of gaming options to suit every taste and budget. Whether players are looking for the thrill of spinning the reels on slot machines or the strategic challenge of table games like blackjack and roulette, these casinos provide an exciting and entertaining experience for everyone. Set against the backdrop of the spectacular Rocky Mountains, these digital gaming platforms are a testament to the ingenuity and innovation of the Canadian gaming industry, inviting players to embark on an exciting adventure where the stakes are high and the rewards are endless.</div><p>The Ancestral Rockies consisted of two main mountain ranges. One, known to geologists as Uncompahgria, stood approximately where today’s <strong>Uncompahgre Plateau</strong> rises in western Colorado. The other, Frontrangia, stood in the same place as today’s Front Range. Whereas today’s Rocky Mountains rise above the <a href="https://coloradoencyclopedia.org/article/colorado’s-great-plains"><strong>Great Plains</strong></a> and Colorado Plateau, Uncompahgria and Frontrangia were mountainous islands that rose from a tropical sea, as Colorado then stood near the equator. Rock eroded from the ranges was deposited along the islands’ coasts and filled the shallow sea in between, where today’s Elk and Sawatch Ranges stand. These layers of conglomerate, sandstone, and mudstone rock form much of the state’s most iconic scenery, including <a href="https://coloradoencyclopedia.org/article/boulder"><strong>Boulder</strong></a>’s <strong>Flatirons</strong>, <a href="https://coloradoencyclopedia.org/article/denver"><strong>Denver</strong></a>’s <a href="https://coloradoencyclopedia.org/article/red-rocks-park-and-amphitheatre"><strong>Red Rocks Amphitheater</strong></a>, <a href="https://coloradoencyclopedia.org/article/roxborough-state-park-archaeological-district"><strong>Roxborough State Park</strong></a>, Balanced Rock at <a href="https://coloradoencyclopedia.org/article/colorado-springs"><strong>Colorado Springs</strong></a>’ <strong>Garden of the Gods</strong>, and <a href="http://www.coloradoencyclopedia.org/article/aspen"><strong>Aspen</strong></a>’s <strong>Maroon Bells</strong>.</p><p>By 150 million years ago, the Ancestral Rockies were eroded down to sea level, and the state was a vast, low-elevation plain reminiscent of Mississippi and Louisiana today. Lazy, meandering rivers that crossed the plain deposited shale and sandstone that make up today’s <strong>Morrison Formation</strong>, which is famous for its rich trove of dinosaur fossils. Many famous Jurassic dinosaur species, including Stegosaurus and Apatosaurus, were first discovered in Colorado’s Morrison Formation.</p><p>About 100 million years ago, the sea level rose, submerging the North American mid-continent. Rivers and erosion from the surrounding land deposited beach sand in Colorado along the flanks of the Western Interior Seaway. Later burial and cementation of that beach sand formed the erosion-resistant <strong>Dakota Sandstone</strong>, which forms an important petroleum reservoir in the <strong>Denver Basin</strong>, one of the nation’s most productive petroleum provinces.</p><p>Colorado continued to sink for roughly the next 30 million years, eventually falling below sea level. The marine mud that accumulated in that shallow sea composes several important rock formations, the thickest being the <strong>Pierre Shale</strong>, which exceeds 8,500 feet thick north of Boulder, and its western Colorado equivalent, the <strong>Mancos Shale</strong>. These shale units contain swelling clay, which presents a major engineering challenge because its movement cracks foundations and heaves pavement.</p><p>As the seaway drained from the state between 70 million and 68 million years ago, it left behind beach sand. The <strong>Fox Hills Sandstone</strong> records the last time Colorado stood at sea level. During the rise of the modern Rocky Mountains, the Fox Hills Sandstone and all older rock layers were tilted down eastward east of the Rockies and down westward west of the mountains. The soft Pierre and Mancos Shale eroded away quickly, as did the equally soft Morrison Formation. That left the erosion-resistant Dakota Sandstone, which was sandwiched in between, to stand as a prominent hogback that marks the foot of the Rocky Mountains. East of the Rockies it forms the famous Dakota Hogback. A roadcut through the hogback marks where <a href="https://coloradoencyclopedia.org/article/interstate-70"><strong>Interstate 70</strong></a> enters the Rockies near <a href="http://www.coloradoencyclopedia.org/article/golden"><strong>Golden</strong></a> and impressive dinosaur footprints cover the Dakota Sandstone at <a href="https://coloradoencyclopedia.org/article/dinosaur-ridge"><strong>Dinosaur Ridge</strong></a>, just south of the cut. West of the Rockies, the Dakota Sandstone and adjacent rock layers form the <strong>Grand Hogback</strong>, a dramatic ridge that runs south-southeast from <a href="https://coloradoencyclopedia.org/article/meeker-0"><strong>Meeker</strong></a> to <strong>New Castle</strong>.</p><p>While the Rocky Mountains of Colorado boast of their natural majesty, Canadian online casinos offer an equally thrilling experience with an attractive offer: 150 free spins for just $1 <a style="color:#494354;" href="https://casinosters.ca/150-free-spins-for-1/">click here</a>. Traveling through the virtual landscape of slot machines and blackjack tables, players can admire the geological wonders that stretch from northern British Columbia to southern New Mexico. The allure of the Rocky Mountains mirrors the excitement of the spinning reels - both promise an unprecedented adventure. In our digital age, borders blur as seamlessly as the horizon stretching across the Rocky Mountains. The combination of Canadian online gaming and the rugged beauty of the Rockies symbolizes the fusion of modern convenience and timeless majesty. As players engage in their gaming adventures, they are reminded of the vast expanse of the Rocky Mountain chain, where peaks pierce the sky and valleys whisper stories of ancient civilizations. The offer of 150 free spins for $1 serves as a gateway to exploration, whether it's conquering virtual mountain peaks or traveling through the breathtaking landscapes that define the heart of North America.</p><h2>Raising the Rockies</h2><p>The rock layers that accumulated in the Western Interior Seaway allow geologists to confidently reconstruct the state’s pre–Rocky Mountain history, but the modern Rockies offer little such evidence. Experts continue to disagree about how and when today’s mountains were built. Three attributes make the Colorado Rockies one of the world’s most puzzling mountain ranges: first, they stand far from a tectonic plate boundary; second, they lack a crustal root; and third, the adjacent Great Plains and Colorado Plateau stand high above sea level despite experiencing minimal folding and faulting. The presence of these high provinces next to the Rockies is unique among world mountain ranges.</p><p>Despite these difficulties, geologists agree that a mountain-building event known as the Laramide Orogeny, which occurred between about 70 million and 45 million years ago, raised Colorado’s mountain ranges. Most also agree that a second, later uplift must have occurred. When and why that second uplift happened are still debated.</p><p>Almost all modern Colorado mountain ranges have <em>thrust faults</em> at their bases. Thrust faults occur when the crust is compressed, which happens when tectonic plates converge. Movement on a thrust fault stacks one slab of rock atop another. That stacking forms mountains. During the Laramide Orogeny, a plate consisting of oceanic material was converging with continental North America off the coast of California. Geologists call such oceanic-continental convergences <em>subduction</em> zones; the plate that possesses oceanic crust is denser than the continental plate, so it dives, or <em>subducts</em>, deep into Earth’s mantle (the layer below the Earth’s crust).</p><p>Normally mountain ranges rise next to subduction zones, but the oceanic plate’s angle of descent dictates exactly how far from the plate boundary compression will be felt. Before 80 million years ago, the oceanic plate converging with continental North America descended at a “normal” angle of about 40–50 degrees. That angle caused compression near the plate boundary, which formed California’s Sierra Nevada Mountains. But after 80 million years ago, the plate’s descent angle became nearly flat, explaining why volcanoes in the Sierra Nevada went extinct just before the start of thrust-fault activity in Colorado.</p><h2>Explaining the Second Uplift</h2><p>Flat-slab subduction can explain why Colorado’s mountains rose far from a plate boundary, but it doesn’t explain the range’s lack of a crustal root or the high elevation of the adjacent Great Plains and Colorado Plateau. The best explanation for those attributes is that the mantle beneath the Rockies is unusually warm. When Colorado’s deep mantle warmed, it expanded and pushed up the overlying crust, lifting the Colorado Rockies as well as the adjacent Great Plains and Colorado Plateau. That warm mantle is also the reason Colorado has so many hot springs.</p><p>Geophysicist Gordon Eaton has called this heat-induced swelling the Alvarado Ridge. The Great Plains and the Colorado Plateau form the eastern and western parts of the Alvarado Ridge, respectively. The older Laramide Rocky Mountains sit atop the ridge, which explains why Colorado’s mountains are so much higher than the rest of the Rocky Mountain chain.</p><h2>When Did the Mantle Warm Up?</h2><p>While geophysicists have documented the warmth of the mantle beneath the Colorado Rockies, they have been unable to deduce <em>when</em> the mantle warmed up. The when and the why of that mantle heating and the associated second uplift event are the subject of current disagreement and research.</p><p>About 38 million years ago, soon after the Laramide Orogeny ended, Colorado erupted in a volcanic episode of giant proportions that lasted until about 24 million years ago; geologists call this episode the Ignimbrite Flare-up. The biggest single volcano ever identified on Earth, the <strong>La Garita Caldera</strong>, is found in Colorado’s San Juan Mountains. It is one of fifteen giant caldera volcanoes in the San Juans, and more big Ignimbrite Flare-up volcanoes or their eroded remnants form peaks in the Elk, West Elk, Sawatch, and Front Ranges. Geologists are not sure what caused this massive volcanic event, but one idea is that the subducting plate that triggered the Laramide Orogeny’s thrust faults also delivered water to Colorado’s subsurface mantle. The addition of water lowers the rock’s melting temperature, which could explain the volcanic activity Regardless, it is clear that a lot of heat would be necessary to produce such large magma volumes; therefore, many geologists believe the mantle warm-up and raising of the Alvarado Ridge occurred about 38–24 million years ago, in conjunction with the Ignimbrite Flare-up.</p><p>Later activity also helps explain the raising of the Alvarado Ridge. About 28 million years ago, just as the Ignimbrite Flare-up was winding down, the Colorado Rockies were stretched and split along the north-south trending <strong>Rio Grande Rift</strong>. The upper <a href="https://coloradoencyclopedia.org/article/arkansas-river"><strong>Arkansas River</strong></a> valley, from <a href="https://coloradoencyclopedia.org/article/leadville"><strong>Leadville</strong></a> to <a href="https://coloradoencyclopedia.org/article/salida"><strong>Salida</strong></a>, lies along this rift, as does the <strong>Rio Grande River</strong>’s southward path along the axis of the <a href="http://www.coloradoencyclopedia.org/article/san-luis-valley"><strong>San Luis Valley</strong></a>. The Rio Grande Rift’s crustal stretching is similar to the stretching that formed today’s famous East African Rift Valley. Such stretching thins the crust, bringing hot mantle closer to the surface, which in turn causes thermal expansion and associated surface uplift. For that reason, many geologists think the Alvarado Ridge rose about 28 million years ago, simultaneous with formation of the Rio Grande Rift.</p><p>Other geologists hypothesize that today’s Colorado Rockies rose to their current height within the last 5 million years. Their primary evidence is that before 5 million years ago, sand and gravel were accumulating across the western Great Plains, producing the Ogallala Formation, the rock unit that forms the important <strong>Ogallala Aquifer</strong>. Sometime after 5 million years ago, the Ogallala Formation was tilted up to the west and the Arkansas and <a href="http://www.coloradoencyclopedia.org/article/south-platte-river"><strong>South Platte</strong></a> Rivers began to erode it. Both the tilting and the erosion might indicate that the Alvarado Ridge rose in the more recent geological past.</p><h2>The Rockies During the Pleistocene Ice Age</h2><p>The modern Rockies might have risen 40, 28, or 5 million years ago. Whenever it was, the newly risen mountains were almost certainly gently rolling uplands; they lacked the steep cliffs and spectacular, deep valleys that make today’s mountains so impressive. The mountains did not achieve their current grandeur until big glaciers sculpted them during the Pleistocene Ice Ages, which began about 2.5 million years ago.</p><p>Periodic changes in Earth’s orbit, called the Milankovitch Cycles, govern the amount of radiation we receive from the sun. About every 100,000 years, the planet cools by about 5 degrees Celsius, which is enough to cause large glaciers to form. Those glacial intervals alternate with interglacial intervals, when the Earth receives more sunlight and the glaciers melt away. The Earth has been in an interglacial interval for about the last 10,000 years, and the peak of the most recent glacial interval was about 20,000 years agowere. Colorado’s mountains were covered by ice caps, and glaciers stretched as long as thirty-five miles down mountain valleys.&nbsp;</p><p>The scouring action of those glaciers deepened the valleys and steepened the ridges and mountain faces, turning the formerly rolling upland into today’s rugged landscape. Calling cards of Colorado’s past glaciers include U-shaped mountain valleys, such as the box canyon where <a href="https://coloradoencyclopedia.org/article/telluride"><strong>Telluride</strong></a> sits, as well as chains of alpine lakes and the craggy nature of many alpine ridges and peaks. Without the combination of the Laramide Orogeny, the post-Laramide uplift of the Alvarado Ridge, and the sculpting action of the Pleistocene glaciers, Colorado would not boast the mountain landscape that brings pleasure to so many locals and visitors today.</p></div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-author--encyclopedia-article.html.twig * field--node--field-author.html.twig x field--node--encyclopedia-article.html.twig * field--field-author.html.twig * field--entity-reference.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <div class="field field--name-field-author field--type-entity-reference field--label-above" id="id-field-author"> <div class="field__label" id="id-field-author">Author</div> <div class='field__items'> <div class="field__item" id="id-field-author"><a href="/author/abbott-lon" hreflang="und">Abbott, Lon</a></div> </div> </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-keyword--encyclopedia-article.html.twig * field--node--field-keyword.html.twig x field--node--encyclopedia-article.html.twig * field--field-keyword.html.twig * field--entity-reference.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <div class="field field--name-field-keyword field--type-entity-reference field--label-above" id="id-field-keyword"> <div class="field__label" id="id-field-keyword">Keywords</div> <div class='field__items'> <div class="field__item" id="id-field-keyword"><a href="/keyword/colorado-geology" hreflang="en">colorado geology</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/geology" hreflang="en">geology</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/formation-rocky-mountains" hreflang="en">formation of rocky mountains</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/mountains" hreflang="en">mountains</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/colorado-mountains" hreflang="en">colorado mountains</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/colorado-rocky-mountains" hreflang="en">colorado rocky mountains</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/geography" hreflang="en">Geography</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/hot-springs" hreflang="en">hot springs</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/red-rocks" hreflang="en">Red Rocks</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/morrison-formation" hreflang="en">Morrison Formation</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/dakota-sandstone" hreflang="en">Dakota sandstone</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/ogallala-aquifer" hreflang="en">ogallala aquifer</a></div> </div> </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'links__node' --> <!-- FILE NAME SUGGESTIONS: * links--node.html.twig x links--inline.html.twig * links--node.html.twig * links.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/navigation/links--inline.html.twig' --> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/navigation/links--inline.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-references-html--encyclopedia-article.html.twig * field--node--field-references-html.html.twig x field--node--encyclopedia-article.html.twig * field--field-references-html.html.twig * field--text-long.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <div class="field field--name-field-references-html field--type-text-long field--label-above" id="id-field-references-html"> <div class="field__label" id="id-field-references-html">References</div> <div class="field__item" id="id-field-references-html"><p>Lon Abbott and Terri Cook, <em>Geology Underfoot Along Colorado’s Front Range</em> (Missoula, MT: Mountain Press, 2012).</p><p>Gordon Eaton, “Epeirogeny in the Southern Rocky Mountains: Evidence and Origin,” <em>Geosphere</em> 4 (2008).</p><p>Eugene Humphreys et al., “How Laramide-Age Hydration of North American Lithosphere by the Farallon Slab Controlled Subsequent Activity in the Western United States,” <em>International Geology Review </em>45 (2003).</p><p>Margaret McMillan, Chris Angevine, and Paul Heller, “Postdepositional Tilt of the Miocene-Pliocene Ogallala Group on the Western Great Plains: Evidence of Late Cenozoic Uplift of the Rocky Mountains,” <em>Geology</em> 30 (2002).</p><p>Peter Molnar and Phillip England, “Late Cenozoic Uplift of Mountain Ranges and Global Climate Change: Chicken or Egg?” <em>Nature</em> 346 (1990).</p><p>Donald Trimble, “Cenozoic Tectonic History of the Great Plains Contrasted With That of the Southern Rocky Mountains: A Synthesis,” <em>Mountain Geologist</em> 17 (1980).</p></div> </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-additional-information-htm--encyclopedia-article.html.twig * field--node--field-additional-information-htm.html.twig x field--node--encyclopedia-article.html.twig * field--field-additional-information-htm.html.twig * field--text-long.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <div class="field field--name-field-additional-information-htm field--type-text-long field--label-above" id="id-field-additional-information-htm"> <div class="field__label" id="id-field-additional-information-htm">Additional Information</div> <div class="field__item" id="id-field-additional-information-htm"><p><a href="http://www.cliffshade.com/colorado/index.htm">Colorado Geology Photojournals</a>.</p><p><a href="https://coloradogeologicalsurvey.org/geology/">Colorado Geological Survey</a>.</p><p><a href="https://igp.colorado.edu/library/">Interactive Geology Project</a>.</p><p>Vincent Matthews,&nbsp;<a href="https://www.worldcat.org/search?q=ti%3A%22Messages%20in%20Stone:%20Colorado%E2%80%99s%20Colorful%20Geology,%22"><em>Messages in Stone: Colorado’s Colorful Geology</em></a>, 2nd ed. (Denver: Colorado Geological Survey, 2009).</p><p>John McPhee, <em>Rising From the Plains</em> (New York: Farrar, Straus and Giroux, 1986).</p></div> </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> Mon, 08 Jun 2020 22:18:06 +0000 yongli 3258 at http://coloradoencyclopedia.org Dinosaur Ridge http://coloradoencyclopedia.org/article/dinosaur-ridge <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--title--encyclopedia-article.html.twig x field--node--title.html.twig * field--node--encyclopedia-article.html.twig * field--title.html.twig * field--string.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--title.html.twig' --> <span class="field field--name-title field--type-string field--label-hidden">Dinosaur Ridge</span> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--title.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--uid--encyclopedia-article.html.twig x field--node--uid.html.twig * field--node--encyclopedia-article.html.twig * field--uid.html.twig * field--entity-reference.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--uid.html.twig' --> <span class="field field--name-uid field--type-entity-reference field--label-hidden"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'username' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/user/username.html.twig' --> <span lang="" about="/users/yongli" typeof="schema:Person" property="schema:name" datatype="">yongli</span> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/user/username.html.twig' --> </span> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--uid.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--created--encyclopedia-article.html.twig x field--node--created.html.twig * field--node--encyclopedia-article.html.twig * field--created.html.twig * field--created.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--created.html.twig' --> <span class="field field--name-created field--type-created field--label-hidden"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'time' --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/time.html.twig' --> <time datetime="2015-11-05T15:41:20-07:00" title="Thursday, November 5, 2015 - 15:41" class="datetime">Thu, 11/05/2015 - 15:41</time> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/time.html.twig' --> </span> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/field/field--node--created.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'addtoany_standard' --> <!-- FILE NAME SUGGESTIONS: * addtoany-standard--node--encyclopedia-article.html.twig * addtoany-standard--node.html.twig x addtoany-standard.html.twig --> <!-- BEGIN OUTPUT from 'modules/contrib/addtoany/templates/addtoany-standard.html.twig' --> <span class="a2a_kit a2a_kit_size_32 addtoany_list" data-a2a-url="http://coloradoencyclopedia.org/article/dinosaur-ridge" data-a2a-title="Dinosaur Ridge"><a class="a2a_dd addtoany_share" href="https://www.addtoany.com/share#url=http%3A%2F%2Fcoloradoencyclopedia.org%2Farticle%2Fdinosaur-ridge&amp;title=Dinosaur%20Ridge"></a><a class="a2a_button_facebook"></a><a class="a2a_button_twitter"></a><a class="a2a_button_email"></a></span> <!-- END OUTPUT from 'modules/contrib/addtoany/templates/addtoany-standard.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--body--encyclopedia-article.html.twig * field--node--body.html.twig x field--node--encyclopedia-article.html.twig * field--body.html.twig * field--text-with-summary.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <div class="field field--name-body field--type-text-with-summary field--label-hidden field__item" id="id-body"><p>Stretching north from <a href="https://coloradoencyclopedia.org/article/morrison"><strong>Morrison</strong></a> to just south of <a href="/article/golden"><strong>Golden</strong></a>, Dinosaur Ridge became famous for the dinosaur fossils and tracks discovered there in 1877. The discoveries, which included the world’s first known <em>Stegosaurus</em> and <em>Apatosaurus</em> fossils, helped launch a “dinosaur rush” in the late nineteenth century. New fossils and tracks continue to be found on the ridge, which is protected by county, state, and federal designations.</p>&#13; &#13; <h2>Geology</h2>&#13; &#13; <p>The rock layers that make up Dinosaur Ridge contain many millions of years of history. During the Jurassic period, about 145 million to 201 million years ago, the area that is now Colorado consisted of a low plain crossed by slow-moving rivers. Dinosaurs lived and died along the rivers. Sometimes their bones were fossilized in the river mud and sand. Rock layers from this period are now known as the Morrison Formation.</p>&#13; &#13; <p>Later, during the Cretaceous period, eastern Colorado was submerged under an inland sea from about 110 million to 70 million years ago. What is now the <a href="https://coloradoencyclopedia.org/article/front-range"><strong>Front Range</strong></a> served for a time as a “freeway” for dinosaurs migrating along the western edge of the inland sea. The rocks from this period are now called the Dakota Group. As sea levels continued to rise, much of Colorado was eventually under <a href="https://coloradoencyclopedia.org/article/water-colorado"><strong>water</strong></a>.</p>&#13; &#13; <p>About 65 million years ago the sea drained, and a sudden uplift called the Laramide orogeny formed huge mountains where the Rockies are today. This activity tilted the old inland seabed at up to a 45-degree angle. Around 40 million years ago, however, the mountains began to quickly erode. A volcanic period known as the Ignimbrite Flare-Up buried them under ash.</p>&#13; &#13; <p>As a result of the flare-up and further erosion, the area we know as the Front Range was essentially a continuation of the <a href="/article/colorado%E2%80%99s-great-plains"><strong>Great Plains</strong></a> as recently as 5 million years ago. At that point a period of intense erosion began, washing away softer rock layers to reveal the much older and harder rocks that make up the Rocky Mountains. The old tilted seabed layers came to the surface as a long chain of ridges, or hogbacks, at the edge of the foothills. Dinosaur Ridge is one of those hogbacks.</p>&#13; &#13; <h2>Early Fossil Discoveries</h2>&#13; &#13; <p><a href="/article/arthur-lakes"><strong>Arthur</strong><strong> Lakes</strong> </a>(1844–1917) discovered the first known fossils on Dinosaur Ridge in 1877. Originally from England, Lakes attended Oxford University before immigrating to the United States in the 1860s. He had arrived in <a href="/article/colorado-territory"><strong>Colorado Territory</strong></a> by 1867. He became a geology instructor at Jarvis Hall in Golden, which developed into the Colorado School of Mines in the 1870s, and he also served as an Episcopal minister, preaching in nearby mining towns.</p>&#13; &#13; <p>On March 20, 1877, Lakes and Henry C. Beckwith, a retired naval officer, were exploring the west side of the hogback just north of Morrison when they came across some large fossilized bones. Lakes recognized them as similar to dinosaur fossils he had seen in England. He sketched the bones and sent his drawings, along with a description of the find, to the paleontologist Othniel Charles Marsh at Yale University. “A few days ago,” he wrote, “I discovered . . . some enormous bones apparently a vertebra and a humerus bone of some gigantic saurian in the Upper Jurassic or Lower Cretaceous at the base of Hayden’s Cretaceous No. 1 Dakotah group.”</p>&#13; &#13; <p>Lakes continued to explore the area. In late April he sent a second letter to Marsh, saying he had found a huge femur indicating an animal about sixty feet long. Marsh, one of the most famous paleontologists in America, did not respond. Nevertheless, in May Lakes shipped Marsh about 2,000 pounds of bones and rocks he had excavated from his quarry near Morrison. Lakes also sent a letter and some bones to Marsh’s main competitor, Edward Drinker Cope, with whom Marsh had a bitter rivalry.</p>&#13; &#13; <p>The possibility of losing the find to his rival finally got Marsh’s attention. Marsh quickly wrote a “Notice of a New and Gigantic Dinosaur” for the July issue of the <em>American Journal of Science</em>, in which he said the new dinosaur “surpassed in magnitude any land animal hitherto discovered.” He hired Lakes as a bone collector and dispatched one of his lead collectors, Benjamin Franklin Mudge, to work with Lakes at the Morrison site. By the middle of July the pair had another 2,500 pounds of rocks and bones ready to ship. Along with a nearly simultaneous discovery of big bones at Como Bluff, Wyoming, the excavations at Dinosaur Ridge marked the start of what has been called the “dinosaur rush” in America.</p>&#13; &#13; <p>Lakes continued to collect bones for Marsh on Dinosaur Ridge until 1879, when he closed his quarries. The new dinosaur genera discovered at Dinosaur Ridge during these years included <em>Allosaurus</em>, <em>Apatosaurus</em>, <em>Diplodocus</em>, and <em>Stegosaurus</em>, the latter of which is now the state fossil of Colorado. In addition, the rock layer in which Lakes made his discoveries was named the Morrison Formation after the town of Morrison.</p>&#13; &#13; <h2>Dinosaur Track Discoveries: Alameda Parkway, 1937</h2>&#13; &#13; <p>Alameda Parkway was extended over Dinosaur Ridge to Red Rocks when the <a href="/article/red-rocks-park-and-amphitheatre"><strong>Red Rocks Amphitheatre</strong></a> was under construction in the late 1930s. Construction exposed rock layers that had previously been hidden or difficult to access. In 1937 workers discovered dinosaur tracks in rock layers from the Dakota Group on the east side of the ridge. New excavations and maps of the tracks in 1992–93 revealed a total of 335 tracks and 37 trackways. Ten different rock strata contain tracks, with at least 78 individual dinosaurs represented in tracks preserved on the ridge.</p>&#13; &#13; <p>The tracks found in the Dakota Group originated 50 million years later than the fossils found in the Morrison Formation. As a result, they represent different dinosaurs. There were few known fossilized bones from this period until recently, so the tracks, which provide evidence about movement and behavior, have played a large role in the way paleontologists understand these dinosaurs.</p>&#13; &#13; <p>The tracks on Dinosaur Ridge primarily record the activity of <em>Iguanadon</em>-like herbivores and ostrich-sized carnivores. The herbivores walked on all fours at about two miles per hour, and evidence of parallel tracks indicates that they traveled in groups. The carnivore tracks, which are about nine inches long, reveal animals that weighed 100 pounds and walked upright on two legs at a speed of five miles per hour. They traveled alone. All these tracks were made about 100 million years ago, when the dinosaurs were migrating north and south on the “Dinosaur Freeway” along the shore of the ancient inland sea.</p>&#13; &#13; <h2>Recent History</h2>&#13; &#13; <p>The nonprofit Friends of Dinosaur Ridge was formed in 1989 to help preserve the site and educate visitors. The group operates a visitor center on the east side of the ridge as well as a newer Discovery Center, which opened in 2014, on the west side of the ridge. The group also maintains West Alameda Parkway over the ridge, which is now closed to vehicle traffic, and has erected a series of interpretive signs to help visitors understand the ridge’s many tracks, bones, and geological features. On the west side of the ridge, Alameda Parkway passes near one of Lakes’s original bone quarries—Quarry #5. In 1995 Friends of Dinosaur Ridge constructed a pedestrian ramp that enables visitors to see the fossils still entombed in rock at the quarry site.</p>&#13; &#13; <p>Lakes’s original quarries on Dinosaur Ridge were closed in 1879, his last year of hunting for fossils on the ridge, and they remained largely dormant for more than 120 years. In the early twenty-first century, researchers at the Morrison Natural History Museum rediscovered one of the quarries and began to examine it again. In 2003 they found the first <em>Stegosaurus </em>footprints ever discovered in Colorado, and in 2006 they made the first discovery in the world of baby <em>Stegosaurus</em> tracks. In early 2016, University of Colorado–Denver geologist Martin Lockley found two-toed raptor tracks on Dinosaur Ridge. The 105-million-year-old tracks were the first two-toed tracks discovered in Colorado and the second ever found in North America.</p>&#13; &#13; <p>Dinosaur Ridge has been recognized multiple times at the federal and state levels as a site with significant historical and scientific value. It has been designated by the National Park Service as a National Natural Landmark (1973), by the state of Colorado as a State Natural Area (2001), and by the Colorado Geological Survey as a Point of Geological Interest (2006). In addition, much of the ridge lies within <a href="https://coloradoencyclopedia.org/article/jefferson-county"><strong>Jefferson County</strong></a>’s Open Space system.</p>&#13; </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-author--encyclopedia-article.html.twig * field--node--field-author.html.twig x field--node--encyclopedia-article.html.twig * field--field-author.html.twig * field--entity-reference.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <div class="field field--name-field-author field--type-entity-reference field--label-above" id="id-field-author"> <div class="field__label" id="id-field-author">Author</div> <div class='field__items'> <div class="field__item" id="id-field-author"><a href="/author/encyclopedia-staff" hreflang="und">Encyclopedia Staff</a></div> </div> </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-keyword--encyclopedia-article.html.twig * field--node--field-keyword.html.twig x field--node--encyclopedia-article.html.twig * field--field-keyword.html.twig * field--entity-reference.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <div class="field field--name-field-keyword field--type-entity-reference field--label-above" id="id-field-keyword"> <div class="field__label" id="id-field-keyword">Keywords</div> <div class='field__items'> <div class="field__item" id="id-field-keyword"><a href="/keyword/morrison-formation" hreflang="en">Morrison Formation</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/dakota-group" hreflang="en">Dakota Group</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/dinosaurs" hreflang="en">dinosaurs</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/hogbacks" hreflang="en">hogbacks</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/paleontology" hreflang="en">paleontology</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/arthur-lakes" hreflang="en">Arthur Lakes</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/morrison-natural-history-museum" hreflang="en">Morrison Natural History Museum</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/stegosaurus" hreflang="en">Stegosaurus</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/apatosaurus" hreflang="en">Apatosaurus</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/allosaurus" hreflang="en">Allosaurus</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/diplodocus" hreflang="en">Diplodocus</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/dinosaur-tracks" hreflang="en">dinosaur tracks</a></div> <div class="field__item" id="id-field-keyword"><a href="/keyword/alameda-parkway" hreflang="en">Alameda Parkway</a></div> </div> </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'links__node' --> <!-- FILE NAME SUGGESTIONS: * links--node.html.twig x links--inline.html.twig * links--node.html.twig * links.html.twig --> <!-- BEGIN OUTPUT from 'themes/contrib/bootstrap_barrio/templates/navigation/links--inline.html.twig' --> <!-- END OUTPUT from 'themes/contrib/bootstrap_barrio/templates/navigation/links--inline.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-references-html--encyclopedia-article.html.twig * field--node--field-references-html.html.twig x field--node--encyclopedia-article.html.twig * field--field-references-html.html.twig * field--text-long.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <div class="field field--name-field-references-html field--type-text-long field--label-above" id="id-field-references-html"> <div class="field__label" id="id-field-references-html">References</div> <div class="field__item" id="id-field-references-html"><p>Lon Abbott and Terri Cook, <em>Geology Underfoot along Colorado's Front Range</em> (Missoula, MT: Mountain Press, 2012).</p>&#13; &#13; <p>Martin Lockley and Lori Marquardt, <em>A Field Guide to Dinosaur Ridge</em>, 2nd ed. (Morrison and Denver: Friends of Dinosaur Ridge and the University of Colorado at Denver Dinosaur Trackers Research Group, 1995).</p>&#13; &#13; <p>Peter J. Modreski, Norbert E. Cygan, Elizabeth P. Rall, and Robert P. Raynolds, "Dinosaur Ridge," <em>Rocks and Minerals</em> 73.5 (September-October 1998).</p>&#13; &#13; <p>Genevieve Rajewski, "<a href="https://www.smithsonianmag.com/history/where-dinosaurs-roamed-36987235/">Where Dinosaurs Roamed</a>," <em>Smithsonian Magazine</em> (May 2008).</p>&#13; &#13; <p>Ann Schrader, "<a href="https://www.denverpost.com/2007/05/21/baby-stegosaurus-tracks/">Baby Stegosaurus Tracks</a>," <em>Denver</em><em> Post</em>, May 22, 2007.</p>&#13; &#13; <p>Emily Williams, "<a href="https://news.ucdenver.edu/first-evidence-of-raptors-discovered-at-dinosaur-ridge/">Researcher Discovers Rare Raptor Tracks</a>," <em>CU Denver Today</em>, February 17, 2016.</p>&#13; </div> </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-additional-information-htm--encyclopedia-article.html.twig * field--node--field-additional-information-htm.html.twig x field--node--encyclopedia-article.html.twig * field--field-additional-information-htm.html.twig * field--text-long.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <div class="field field--name-field-additional-information-htm field--type-text-long field--label-above" id="id-field-additional-information-htm"> <div class="field__label" id="id-field-additional-information-htm">Additional Information</div> <div class="field__item" id="id-field-additional-information-htm"><p><a href="https://dinoridge.org/index.html">Friends of Dinosaur Ridge</a>.</p>&#13; &#13; <p>Katherine K. Honda and Beth Simmons, <em>The Legacy of Arthur Lakes</em> (Morrison, CO: Friends of Dinosaur Ridge, 2009).</p>&#13; &#13; <p>Michael F. Kohl and John S. McIntosh, eds., <em>Discovering Dinosaurs in the Old West: The Field Journals of Arthur Lakes</em> (Washington, DC: Smithsonian Institution Press, 1997).</p>&#13; </div> </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-4th-grade--encyclopedia-article.html.twig * field--node--field-4th-grade.html.twig x field--node--encyclopedia-article.html.twig * field--field-4th-grade.html.twig * field--text-with-summary.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <div class="field field--name-field-4th-grade field--type-text-with-summary field--label-hidden field__item" id="id-field-4th-grade"><p>Dinosaur Ridge is a place where many dinosaur fossils and tracks were discovered. The world’s first known Stegosaurus and Apatosaurus fossils were found at the site. New fossils and tracks continue to be found on the ridge. It is located near Red Rocks Amphitheater and the town of Morrison.</p>&#13; &#13; <h2>Geology</h2>&#13; &#13; <p>Dinosaur Ridge contains millions of years of history. The Jurassic period was 145 to 201 million years ago. Then, the area was a plain crossed by rivers. Dinosaurs lived and died along the rivers. Some of their bones were fossilized in the mud and sand.</p>&#13; &#13; <p>Later came the Cretaceous period. It was 110 million to 70 million years ago. Colorado was covered by an inland sea. Dinosaurs moved along the edge of the sea. Sea levels continued to rise. Much of Colorado was under water.</p>&#13; &#13; <p>About 65 million years ago, the sea drained. An uplift formed huge mountains where the Rockies are today. The old inland seabed tilted up to a 45-degree angle. Volcanoes buried the mountains under ash.</p>&#13; &#13; <p>Then, around 40 million years ago, the mountains began to erode. The ash and soft rock layers wore away. The older rocks that make up the Rocky Mountains were uncovered. The old tilted seabed came to the surface. It became the ridges along the edge of the foothills. The ridges are called “hogbacks.” Dinosaur Ridge is one of those hogbacks.</p>&#13; &#13; <h2>Early Fossil Discoveries</h2>&#13; &#13; <p>Arthur Lakes discovered the first fossils on Dinosaur Ridge. He was from England. He immigrated to the United States in the 1860s. The Colorado School of Mines hired him as a geology teacher. He also worked as a minister, preaching in mining towns.</p>&#13; &#13; <p>In 1877 Lakes was exploring the hogback. He came across some large fossilized bones. They reminded him of dinosaur fossils he had seen in England. He sketched what he saw. He sent his drawings to Othniel Charles Marsh at Yale University. Marsh was one of the most famous paleontologists in America. Lakes did not hear back from Marsh.</p>&#13; &#13; <p>Lakes continued to explore the area. In late April he sent a second letter to Marsh. He told him he had found a huge leg bone. He said he believed the animal had been enormous. Again, Marsh did not respond to the letter. So Lakes sent him some bones and rocks. But this time, Lakes also sent a letter and some bones to Edward Drinker Cope. Cope wanted to be a more famous paleontologist than Marsh.</p>&#13; &#13; <p>This finally got Marsh’s attention. Marsh wrote an article about the gigantic dinosaur for the American Journal of Science. He said the new dinosaur was the biggest ever discovered. He hired Lakes as a bone collector. Soon 2,500 pounds of rocks and bones were sent to Marsh. There was another discovery of dinosaur bones in Wyoming. These finds started what has been called the “dinosaur rush” in America.</p>&#13; &#13; <p>Lakes continued to collect bones on Dinosaur Ridge until 1879. New species of dinosaurs were discovered at Dinosaur Ridge. They include Allosaurus, Apatosaurus, Diplodocus, and Stegosaurus. The Stegosaurus was later named the state fossil of Colorado.</p>&#13; &#13; <h2>Dinosaur Track Discoveries</h2>&#13; &#13; <p>Red Rocks Amphitheater was built in the 1930s. A new road to Red Rocks uncovered more rock layers. Workers discovered dinosaur tracks. By 1993, 335 tracks had been uncovered.</p>&#13; &#13; <p>The tracks and the bones were from different time periods. The tracks provided information about dinosaur movement and behavior. The discovery helped paleontologists understand dinosaurs better.</p>&#13; &#13; <p>The tracks on Dinosaur Ridge were made by Iguanadon-like herbivores and ostrich-sized carnivores. The herbivores walked on four legs at about two miles per hour. They traveled in groups. The carnivore tracks show that they weighed 100 pounds. They walked on two legs. They could move five miles per hour and traveled alone. These dinosaurs were migrating along the shore of the ancient sea. The tracks were made about 100 million years ago.</p>&#13; &#13; <h2>Recent History</h2>&#13; &#13; <p>The group Friends of Dinosaur Ridge was formed in 1989. It helps preserve the site and educate visitors. The group operates a visitor center and a Discovery Center. The road over the hogback is now closed to cars. Visitors can walk along paths and see the tracks and bones. There are signs that help visitors understand the area. Visitors can see one of Lakes’ original bone pits.</p>&#13; &#13; <p>Lakes’ digging sites on Dinosaur Ridge were closed in 1879. No one explored them for more than 120 years. In the 2000s, one of his old pits was investigated. Scientists found Stegosaurus footprints. Later, they discovered baby Stegosaurus tracks. They also found two-toed raptor tracks. These were the first two-toed tracks discovered in Colorado.</p>&#13; &#13; <p>Dinosaur Ridge is a site of historical and scientific value. The National Park Service named it a National Natural Landmark. The state of Colorado calls it a State Natural Area. The Colorado Geological Survey has made it a Point of Geological Interest. </p>&#13; </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-8th-grade--encyclopedia-article.html.twig * field--node--field-8th-grade.html.twig x field--node--encyclopedia-article.html.twig * field--field-8th-grade.html.twig * field--text-with-summary.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <div class="field field--name-field-8th-grade field--type-text-with-summary field--label-hidden field__item" id="id-field-8th-grade"><p>Located on a hogback near the town of Morrison, Dinosaur Ridge is famous for the discovery of dinosaur fossils and tracks. The findings include the world’s first known Stegosaurus and Apatosaurus fossils. New fossils and tracks continue to be found on the ridge.</p>&#13; &#13; <h2>Geology</h2>&#13; &#13; <p>The rock layers that make up Dinosaur Ridge contain millions of years of history. During the Jurassic period (145–201 million years ago) the area was a low plain crossed by rivers. Dinosaurs lived and died along the rivers. Sometimes their bones were fossilized in the river mud and sand. Rock layers from this period are now known as the Morrison Formation.</p>&#13; &#13; <p>Later, during the Cretaceous period (110–70 million years ago) Colorado was covered by an inland sea. Dinosaurs moved along the edge of the sea. The rocks from this period are now called the Dakota Group. As sea levels continued to rise, much of Colorado was under water.</p>&#13; &#13; <p>About 65 million years ago the sea drained. A sudden uplift called the Laramide orogeny formed huge mountains where the Rockies are today. This activity tilted the old inland seabed up to a 45-degree angle. Then, around 40 million years ago, the mountains began to erode. A volcanic period known as the Ignimbrite Flare-Up buried the mountains under ash.</p>&#13; &#13; <p>Five million years ago, the area looked like part of the Great Plains. Then, a period of erosion began. The ash and softer rock layers wore away. The older and harder rocks that make up the Rocky Mountains were uncovered. The old tilted seabed layers came to the surface. They formed a long chain of ridges along the edge of the foothills. The ridges are called “hogbacks.” Dinosaur Ridge is one of those hogbacks.</p>&#13; &#13; <h2>Early Fossil Discoveries</h2>&#13; &#13; <p>Arthur Lakes discovered the first known fossils on Dinosaur Ridge in 1877. He was from England and attended Oxford University. He immigrated to the United States in the 1860s. Colorado School of Mines hired him as a geology teacher. He also served as an Episcopal minister, preaching in nearby mining towns.</p>&#13; &#13; <p>In March 1877, Lakes and Henry C. Beckwith were exploring the west side of the hogback. They came across some large fossilized bones. They reminded Lakes of dinosaur fossils he had seen in England. He sketched the bones. He sent his drawings and a description to paleontologist Othniel Charles Marsh at Yale University. Marsh was one of the most famous paleontologists in America. Lakes did not hear back from Marsh.</p>&#13; &#13; <p>Lakes continued to explore the area. In late April he sent a second letter to Marsh, saying he had found a huge leg bone. He believed the animal had been about sixty feet long. Again, Marsh did not respond to his letter. So Lakes shipped him bones and rocks he had excavated from the site. But this time, Lakes also sent a letter and some bones to Marsh’s main competitor, Edward Drinker Cope. Marsh and Cope were competing to be America’s most noted paleontologist.</p>&#13; &#13; <p>The possibility of losing the find to his rival finally got Marsh’s attention. Marsh published an article titled “Notice of a New and Gigantic Dinosaur” for the American Journal of Science. He wrote that the new dinosaur was the biggest ever discovered. He hired Lakes as a bone collector. By the middle of July, Lakes had 2,500 pounds of rocks and bones ready to ship. There had also been another discovery of big bones at Como Bluff, Wyoming. These finds started the “dinosaur rush” in America.</p>&#13; &#13; <p>Lakes continued to collect bones for Marsh on Dinosaur Ridge until 1879. New species of dinosaurs were discovered at Dinosaur Ridge, including Allosaurus, Apatosaurus, Diplodocus, and Stegosaurus. The Stegosaurus was later named the state fossil of Colorado.</p>&#13; &#13; <h2>Dinosaur Track Discoveries</h2>&#13; &#13; <p>Red Rocks Amphitheater was built in the 1930s. The construction of a road to Red Rocks exposed rock layers that had been hidden. In 1937 workers discovered dinosaur tracks from the Dakota Group on the ridge. By 1993 they had mapped 335 tracks. The tracks of at least seventy-eight individual dinosaurs are preserved on the ridge. The tracks provide information about dinosaur movement and behavior.</p>&#13; &#13; <p>The tracks on Dinosaur Ridge are from Iguanadon-like herbivores and ostrich-sized carnivores. The herbivores walked on four legs at about two miles per hour and traveled in groups. The carnivore tracks show that the animals weighed 100 pounds. They walked upright on two legs at a speed of five miles per hour and traveled alone. The dinosaurs were migrating on the “Dinosaur Freeway” along the shore of the ancient sea.</p>&#13; &#13; <h2>Recent History</h2>&#13; &#13; <p>The nonprofit Friends of Dinosaur Ridge was formed in 1989. The group helps preserve the site and educate visitors. It operates a visitor center and a discovery center. The road over the hogback is now closed to cars. Visitors can walk along paths and see the tracks and bones. Interpretive signs help visitors understand the ridge’s many tracks, bones, and geological features. Visitors can also see one of Lakes’s original bone quarries.</p>&#13; &#13; <p>Lakes’ original quarries on Dinosaur Ridge were closed in 1879. No one explored them for more than 120 years. In the early twenty-first century, researchers rediscovered the quarries and began to examine them again. In 2003 they found the first Stegosaurus footprints ever discovered in Colorado. Later, they discovered baby Stegosaurus tracks. They also found two-toed raptor tracks on Dinosaur Ridge. The 105-million-year-old tracks were the first two-toed tracks discovered in Colorado.</p>&#13; &#13; <p>Dinosaur Ridge has been recognized as a site with significant historical and scientific value. It has been designated by the National Park Service as a National Natural Landmark (1973). The state of Colorado named it as a State Natural Area (2001). The Colorado Geological Survey calls it a Point of Geological Interest (2006).</p>&#13; </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-10th-grade--encyclopedia-article.html.twig * field--node--field-10th-grade.html.twig x field--node--encyclopedia-article.html.twig * field--field-10th-grade.html.twig * field--text-with-summary.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> <div class="field field--name-field-10th-grade field--type-text-with-summary field--label-hidden field__item" id="id-field-10th-grade"><p>Dinosaur Ridge is a hogback located near the town of Morrison that is famous for the dinosaur fossils and tracks discovered there. The discoveries include the world’s first known Stegosaurus and Apatosaurus fossils. New fossils and tracks continue to be found on the ridge.</p>&#13; &#13; <h2>Geology</h2>&#13; &#13; <p>The rock layers that make up Dinosaur Ridge contain millions of years of history. During the Jurassic period (about 145–201 million years ago) the area that is now Colorado was a low plain crossed by slow-moving rivers. Dinosaurs lived and died along the rivers. Sometimes their bones were fossilized in the river mud and sand. Rock layers from this period are now known as the Morrison Formation.</p>&#13; &#13; <p>Later, during the Cretaceous period (about 110–70 million years ago) eastern Colorado was submerged under an inland sea. What is now the Front Range served a migration route along the western edge of the sea. The rocks from this period are called the Dakota Group. As sea levels continued to rise, much of Colorado was covered with water.</p>&#13; &#13; <p>About 65 million years ago the sea drained. A sudden uplift called the Laramide orogeny formed huge mountains where the Rockies are today. This activity tilted the old inland seabed up at a 45-degree angle. Then, around 40 million years ago, the mountains began to erode. A volcanic period known as the Ignimbrite Flare-Up buried the mountains under ash.</p>&#13; &#13; <p>Five million years ago, the area we know as the Front Range was a continuation of the Great Plains. At that point, a period of intense erosion began. Ash and softer rock layers wore away. The older and harder rocks that make up the Rocky Mountains were uncovered. The tilted seabed layers came to the surface. They formed a long chain of ridges or hogbacks along the edge of the foothills. Dinosaur Ridge is one of those hogbacks.</p>&#13; &#13; <h2>Early Fossil Discoveries</h2>&#13; &#13; <p>Arthur Lakes (1844–1917) discovered the first known fossils on Dinosaur Ridge in 1877. Originally from England, Lakes attended Oxford University before immigrating to the United States in the 1860s. He arrived in Colorado Territory by 1867. He became a geology instructor at Jarvis Hall in Golden. That school became the Colorado School of Mines in the 1870s. He also served as an Episcopal minister, preaching in nearby mining towns.</p>&#13; &#13; <p>On March 20, 1877, Lakes and Henry C. Beckwith, a retired naval officer, were exploring the west side of the hogback. They came across some large fossilized bones. Lakes recognized them as similar to dinosaur fossils he had seen in England. He sketched the bones and sent his drawings and a description to paleontologist Othniel Charles Marsh at Yale University. Marsh was one of the most famous paleontologists in America, telling him that he had found “some enormous bones … at the base of Hayden’s Cretaceous No. 1 Dakota group.” He did not hear back from Marsh.</p>&#13; &#13; <p>Lakes continued to explore the area. In April he sent a second letter to Marsh, saying he had found a huge femur indicating an animal about sixty feet long. Again, Marsh did not respond. Nevertheless, Lakes shipped Marsh about 2,000 pounds of bones and rocks he had excavated from the site. Lakes also sent a letter and some bones to Marsh’s main competitor, Edward Drinker Cope. Marsh and Cope had a bitter rivalry.</p>&#13; &#13; <p>The possibility of losing the find to his rival finally got Marsh’s attention. Marsh wrote a “Notice of a New and Gigantic Dinosaur” for the July issue of the American Journal of Science. He said the new dinosaur “surpassed in magnitude any land animal hitherto discovered.” He hired Lakes as a bone collector and sent one of his collectors, Benjamin Franklin Mudge, to work with Lakes. By the middle of July the pair had another 2,500 pounds of rocks and bones ready to ship. There had been a similar discovery of big bones at Como Bluff, Wyoming. These finds started what has been called the “dinosaur rush” in America.</p>&#13; &#13; <p>Lakes continued to collect bones for Marsh on Dinosaur Ridge until 1879. The new dinosaurs discovered at Dinosaur Ridge during these years include Allosaurus, Apatosaurus, Diplodocus, and Stegosaurus. The Stegosaurus was named the state fossil of Colorado.</p>&#13; &#13; <h2>Dinosaur Track Discoveries</h2>&#13; &#13; <p>When Red Rocks Amphitheatre was built in the l930s, Alameda Parkway was extended over Dinosaur Ridge. The construction exposed rock layers that had been hidden or difficult to access. In 1937 workers discovered dinosaur tracks from the Dakota Group on the east side of the ridge. Excavations and maps of the tracks show a total of 335 tracks and 37 trackways. Ten different rock strata contain tracks, with at least seventy-eight individual dinosaurs making the tracks preserved on the ridge.</p>&#13; &#13; <p>The tracks found in the Dakota Group were made 50 million years later than the fossils found in the Morrison Formation. The bones and the tracks were from dinosaurs of different geologic periods. There were few known fossilized bones from this period. The tracks provided information about dinosaur movement and behavior. The discovery played a large role in the way paleontologists understand these dinosaurs.</p>&#13; &#13; <p>The tracks on Dinosaur Ridge show the movement of Iguanadon-like herbivores and ostrich-sized carnivores. The herbivores walked on all fours at about two miles per hour. Evidence of parallel tracks indicates that they traveled in groups. The carnivore tracks, which are about nine inches long, reveal animals that weighed 100 pounds. They walked upright on two legs at a speed of five miles per hour. They traveled alone. All these tracks were made about 100 million years ago, when the dinosaurs were migrating on the “Dinosaur Freeway” along the shore of the ancient inland sea.</p>&#13; &#13; <h2>Recent History</h2>&#13; &#13; <p>The nonprofit Friends of Dinosaur Ridge was formed in 1989 to help preserve the site and educate visitors. The group operates a visitor center and a Discovery Center. The group maintains West Alameda Parkway over the ridge, which is now closed to vehicle traffic. They have put up a series of interpretive signs to help visitors understand the ridge’s many tracks, bones, and geological features. On the west side of the ridge, Alameda Parkway passes near one of Lakes’ original bone quarries—Quarry #5. In 1995 Friends of Dinosaur Ridge built a pedestrian ramp that enables visitors to see the fossils still entombed in rock at the quarry site.</p>&#13; &#13; <p>Lakes’ original quarries on Dinosaur Ridge were closed in 1879, his last year of hunting for fossils on the ridge. They remained dormant for more than 120 years. In the early 2000s, researchers at the Morrison Natural History Museum rediscovered one of the quarries. They began to examine it again. In 2003 they found the first Stegosaurus footprints ever discovered in Colorado. In 2006 they made the first discovery in the world of baby Stegosaurus tracks. In early 2016, University of Colorado–Denver geologist Martin Lockley found two-toed raptor tracks on Dinosaur Ridge. The 105-million-year-old tracks were the first two-toed tracks discovered in Colorado and the second ever found in North America.</p>&#13; &#13; <p>Dinosaur Ridge has been recognized at the federal and state levels as a site with significant historical and scientific value. It has been designated by the National Park Service as a National Natural Landmark (1973), by the state of Colorado as a State Natural Area (2001), and by the Colorado Geological Survey as a Point of Geological Interest (2006). In addition, much of the ridge lies within Jefferson County’s Open Space system.</p>&#13; </div> <!-- END OUTPUT from 'themes/custom/encyclopedia/templates/field/field--node--encyclopedia-article.html.twig' --> Thu, 05 Nov 2015 22:41:20 +0000 yongli 812 at http://coloradoencyclopedia.org