Clear Creek flows from the Continental Divide at Loveland Pass, eastward through a deep and wide glacial valley down to Idaho Springs, where the valley narrows and the stream gradient increases as it enters narrow, relatively undeveloped Clear Creek Canyon. Through Clear Creek Canyon the stream rushes twenty miles in continuous rapids through deep rocky gorges to Golden, where it widens and becomes gentle again. Other than the two-lane US Highway 6, which hugs the creek, the canyon is nearly pristine, providing a major wilderness recreational area at the western edge of the Denver metro area. Hikers, mountain bikers, rafters, rock climbers, and anglers, as well as those seeking a simple day away from the city with family and friends, all enjoy this beloved landscape.
Clear Creek Canyon is cut into highly resistant granite and gneiss bedrock, originally formed deep beneath ancient mountain ranges 25 million years ago. Many periods of subsequent faulting, uplift, and erosion brought these rocks to the surface some 40 million years ago, when Colorado was at a much lower elevation. This area had gently rolling hills then, and Clear Creek flowed eastward in roughly the same position it is today. As uplift was subsequently renewed (mainly in the last 10 million years), Clear Creek cut a 600-foot-deep canyon through a roughly two-mile-wide valley with steep walls and a wide gentle floor. Stream gravel deposited at that time is still preserved in places where remnants of this gentle valley bottom have not been removed by later erosion. Over the last few million years, Clear Creek was rejuvenated and cut a narrow, 1,000-foot-deep, V-shaped inner gorge into this older gentle valley to produce what is called the “inner canyon.”
Only the inner gorge is visible from creek level, and travelers on Highway 6 are unaware of gentler terrain left from the earlier, wider valley preserved high above them. Clear Creek has a high gradient and is still actively deepening the gorge. As the creek cuts downward, canyon walls retreat via frequent rock falls, debris flows, landslides, and flash floods that sometimes close the highway, which is also subject to washouts by Clear Creek itself. Walls of the inner gorge vary from nearly vertical (where the bedrock is most resistant to erosion) to more gently sloping walls (where the bedrock is less resistant or has been fractured in old fault zones). Just west of Golden, where Clear Creek crosses the Golden fault and enters soft, easily eroded sedimentary rocks, the canyon abruptly and spectacularly ends at the mountain front, giving way to the wide and inviting Golden Valley.
Clear Creek receives three major tributaries in the canyon, North Clear Creek (at about mile 12) and Guy Gulch (at about mile 5), both entering from the north, and Beaver Brook (at about mile 7) from the south. North Clear Creek flows down from the old Central City and Black Hawk mining districts, which have in recent years been converted to gambling centers. North Clear Creek supplies significant sediment to Clear Creek when flowing high during storms. Guy Gulch, smaller than North Clear Creek, flows from the south side of Golden Gate Canyon State Park through a wide, low-gradient valley, not visible from Clear Creek itself, before entering Clear Creek through a narrow gorge. Beaver Brook flows from Squaw Mountain and enters Clear Creek behind highway tunnel 2 through a narrow gorge. Most other tributaries in the canyon, many of which are unnamed, are small and steep.
Clear Creek Canyon is oriented in an east-west direction, so the north and south sides of the canyon have very different vegetation. Canyon slopes north of Clear Creek face south and receive intense, high-angle sunlight, causing soils to be dry and thin. Snow disappears quickly from these inclines after winter storms. Slopes south of Clear Creek face north, and sunlight strikes them at a low angle; some steep slopes receive almost no direct sunlight during the winter months. Consequently, soils tend to be thicker and moister. The north side of the canyon is primarily covered by bunch grass or low brush (especially mountain mahogany) with scattered Rocky Mountain juniper trees. Open ponderosa pine forests develop on the higher slopes. The south side of the canyon is mainly forest covered with open ponderosa forest on ridges and thick ponderosa pine–Douglas fir forests on most slopes. Underbrush is thick with mountain mahogany, Rocky Mountain maple, and a variety of other shrubs. Colorado blue spruce trees grow along the larger drainages, which may contain perennial, spring-fed streams.
The foothills and valleys that surround Clear Creek Canyon, and the benches that parallel it, were the hunting grounds and travel routes for the Arapaho and Ute peoples, and several prehistoric sites are recorded in the area. Early settlers in the 1800s, however, found the narrow, rugged, canyon a barrier to transportation. When gold was discovered and developed in Idaho Springs and Central City in the 1860s, mines were accessed from Golden via toll roads that followed ancient Native American trails along the higher areas north (Golden Gate Canyon route), and south (Mt. Vernon Canyon route) of Clear Creek Canyon. In 1872 the narrow-gauge Colorado Central Railroad was built up the canyon along a grade just above creek level. One branch of the line extended up North Clear Creek to Black Hawk and Central City. Another branch followed Clear Creek up to Idaho Springs and ultimately reached Georgetown and beyond in 1878.
The railroad opened the area to tourism, and the canyon became a major scenic and recreational destination, famous for its spectacular cliffs. At Beaver Brook, midway through the canyon, the railroad built a small siding to allow passengers access to hiking trails and built a dance pavilion on the slope above it. As mining waned in the twentieth century, the railroad became unprofitable and the rails were removed in 1941. Construction of US Highway 6 through the canyon began in the late 1930s, often on top of the old railroad grade, and opened in 1952. In 1938 State Highway 119 was rerouted to intersect US Highway 6 and follow the railroad grade up North Clear Creek to Black Hawk. At especially narrow or circuitous sections of the canyon, six tunnels were bored through ridges to accommodate the highway. The old railroad grade is still preserved behind these tunnels. In 2014, Great Outdoors Colorado, Jefferson County Open Space, and Clear Creek County Open Space started construction of a paved bicycle path, which will one day connect Golden to the Continental Divide using the old railroad grade where possible.
Clear Creek Canyon has remained remarkably free from the highway-based development that crowds most Front Range canyons. There are no buildings in the inner gorge, and most of the outer gorge has escaped encroachment by home construction and attendant roads. Although all the land was homesteaded in the late 1800s and used for cattle grazing and local hay production, a combination of rugged landscape, enlightened landowners, and local residents allowed it to remain undeveloped into the 1980s, when a combination of public and private land conservation efforts started the process of limiting development forever.
In 1986, local residents created the Clear Creek Land Conservancy, which began conservation of land along the Beaver Brook trail through conservation easements and promoted further conservation by public and private entities. Jefferson County Open Space owns the land adjacent to Clear Creek, from Golden to the Clear Creek County line, and has preserved hundreds of acres of land on the canyon slopes in Clear Creek, Centennial Cone, Mt. Galbraith, and Windy Saddle Parks. Clear Creek County Open Space manages many acres of open space in the canyon between Highway 40 and Highway 119, and much of the lower portion of Beaver Brook is preserved in Denver Mountain Parks’ Genesee Park. The Clear Creek Land Conservancy owns 600 acres on the south side of the canyon and holds conservation easements on 1,300 additional acres of private land, ensuring it will never be developed.
Trails in the canyon include the historic Beaver Brook Trail, which extends eight miles along the south side inner bench from Windy Saddle Park to Genesee Park. Centennial Cone Park on the northwest side of the canyon has an extensive trail system, accessible from the canyon bottom at Mayhem Gulch as well as from two trailheads on Douglas Mountain Drive and Robinson Hill Road.
Conservation work remains. There are several large private land holdings on both sides of the canyon. If these are one day conserved, Clear Creek Canyon will be, and remain, the premier wilderness canyon of the Front Range.