Skip to main content

Rocky Mountain Elk

    Rocky Mountain Elk (Cervus canadensis nelsoni) are large mammals in the deer family that live in Colorado’s forests. Revered as a symbol of the American West, they have played an important role in Colorado’s ecology and natural history. Each year, millions of people travel to Rocky Mountain National Park and Colorado’s National Forests to catch a glimpse of these animals. In addition to drawing tourists, the state’s elk populations also attract hunters from around the globe.

    Ecology

    Historically, Colorado’s elk populations have oscillated widely. Elk, or wapiti—a Shawnee Indian term for the animals—moved across the Bering Strait from Asia at least 120,000 years ago. Their distribution and abundance in North America ebbed and flowed in relation to periods of glaciation, but they roamed from northern Canada into Mexico. Elk arrived in northern Colorado about 8,000–10,000 years ago and in southern Colorado about 4,000–5,000 years ago. Historical estimates suggest that the elk population might have exceeded 10 million prior to European arrival on the continent in 1492.

    The North American elk is a gregarious grazer, feeding mostly on grasses and forbs instead of shrubs. Their current preference for forest cover is thought to be an innovation, as their herding behavior is typical of mammals that live in open country. Winter elk herds are large, ranging from fifty to several hundred individuals of both sexes. Winter herds disband as bulls move first to summer range, following the retreating snowline and the advance of green herbage. Cow and calves follow bulls to summer range, and the great winter herds break up into smaller bands.

    The crisp air of late September carries the bugling of bulls, signaling the beginning of the rut, or mating, season. Contrary to popular belief, bugling is neither a challenge nor a threat. It is partly a release of tension built up during the bull’s seasonal changes; the shoulders and neck swell with the rut, and antlers sharpen. Bugling peaks in early October, and the most aggressive bulls assert authority over bands of five to fifteen cows. Another bull may challenge that authority through sparring, an antler-clashing battle for dominance.

    Gestation takes about 250 days, and a single calf weighing about thirty-three pounds is born in June. With an odor seemingly detectable only by the mother, the calf remains motionless and is left alone as the mother forages. As typical of ungulates, the calves are mobile within hours of birth. The calf develops quickly and is usually weaned by late summer. At six months it may weigh 265 pounds. Cows are mature by their second autumn and usually begin reproducing after three years. Because of the social structure of the herd, bulls do not generally acquire cows and begin breeding until their fourth or fifth year.

    At one time gray wolves preyed on elk, and mountain lions still take a few annually. A pack of coyotes can kill a weakened elk or one immobilized by deep snow. As with deer, moose, and caribou, elk harbor parasites, including flukes, tapeworms and roundworms, lice, botflies, and mites. Chronic wasting disease (CWD)a contagious neurological disease affecting the brains of deer, moose, and elk—is known in some Colorado elk populations, including those in Rocky Mountain National Park. CWD predominantly affects adult animals and typically results in dramatic behavioral changes. Infected elk are less social and may suffer from tremors, listlessness, nervousness, and excessive salivation, the latter which is thought to contribute to the spread of the disease. CWD’s common denominator is chronic weight loss, which ultimately leads to death.

    Human Interaction

    Where elk appeared in abundance, indigenous peoples hunted them for food, clothing, and tools. In Colorado, Navajo, Ute, Jicarilla Apache, Havasupai, Hopi, Zuni, and other peoples harvested elk in the southern Rocky Mountains and the Four Corners region.

    The pre-European period of abundance ended abruptly in the mid-nineteenth century. As white settlement and railroads moved westward, elk, bison, deer, and bighorn sheep were hunted to feed the growing western population and to suppress Native Americans. This reduced the elk population from an estimated 10 million to fewer than 100,000 in 1907 and approximately 90,000 in 1922. About one-third of those elk lived in the Yellowstone area and Canada.

    Colorado’s elk had a similar experience. The Colorado Gold Rush of 1858–59 ushered in a period of intense exploitation that did not cease until the early 1900s, when Colorado began enacting strict hunting regulations to conserve its remaining elk. The US Forest Service estimated that Colorado’s 1910 population contained 500 to 1,000 head of elk, with the largest herds in the White and Gunnison watersheds. The diminishing elk herds prompted Colorado to halt elk hunting throughout most of the state from 1903 to 1933. From 1912 to 1928, the Colorado Department of Game and Fish (the predecessor to Colorado Parks and Wildlife) reintroduced 350 elk from Jackson Hole, Wyoming, into fourteen areas, including the Hermosa Creek drainage north of Durango in 1912. During the 1930s, after elk populations had rebounded, the state trapped elk from abundant herds in southwest Colorado and transplanted them to other states to begin new herds.

    Return to Abundance

    Elk have been successfully restored to Colorado. In fact, with an estimated elk population of 280,000, the state hosts the largest elk population in North America. The relatively docile ungulates may be a reliable tourist draw, but excessively large elk populations can result in overgrazing that threatens ecosystem stability.

    With humans having severely reduced the state’s population of mountain lions, wolves, and coyotes, state and federal wildlife officials use artificial strategies such as hunting and culling to manage elk populations. About 250,000 hunters pursue elk each year in Colorado, harvesting nearly 50,000. Culling, meanwhile, involves killing off fertile females when the elk population approaches a predetermined peak population. The need for such lethal management strategies demonstrates that Colorado’s elk population has cycled back to abundance after its severe reduction in the nineteenth and early twentieth centuries.

    Adapted from Scott Wait and Mike Japhet, “Wildlife of the San Juans: A Story of Abundance and Exploitation,” in The Eastern San Juan Mountains: Their Geology, Ecology, and Human History, ed. Rob Blair and George Bracksieck (Boulder: University Press of Colorado, 2011) and David M. Armstrong, “Order Artiodactyla: Even-toed Hoofed Mammals,” in Rocky Mountain Mammals: A Handbook of Mammals of Rocky Mountain National Park and Vicinity, 3rd ed. (Boulder: University Press of Colorado, 2008).

    Rocky Mountain Elk (Cervus canadensis nelsoni) are large mammals in the deer family that live in Colorado’s forests. They have played an important role in Colorado’s ecology and natural history. Each year, millions of people travel to Rocky Mountain National Park and Colorado’s National Forests to see these animals. In addition to drawing tourists, the state’s elk populations also attract hunters from around the globe.

    Ecology

    Colorado’s elk populations have changed over time. Elk moved across the Bering Strait from Asia at least 120,000 years ago. Elk arrived in northern Colorado about 8,000–10,000 years ago and in southern Colorado about 4,000–5,000 years ago. Historical estimates suggest that the elk population might have exceeded 10 million prior to European arrival in 1492.

    The North American elk is a gregarious grazer, feeding mostly on grasses and forbs instead of shrubs. Their current preference for forest cover is thought to be an innovation. Their herding behavior is typical of mammals that live in open country. Winter elk herds are large, ranging from fifty to several hundred individuals of both sexes. Winter herds disband as bulls move to summer range. Cow and calves follow bulls to summer range, and the great winter herds break up into smaller bands.

    The crisp air of late September carries the bugling of bulls, signaling the beginning of the rut, or mating, season. Contrary to popular belief, bugling is neither a challenge nor a threat. It is partly a release of tension built up during the bull’s seasonal changes; the shoulders and neck swell with the rut, and antlers sharpen. Bugling peaks in early October, and the most aggressive bulls assert authority over bands of five to fifteen cows. Another bull may challenge that authority through sparring, an antler-clashing battle for dominance.

    Gestation takes about 250 days, and a single calf weighing about thirty-three pounds is born in June. The calf remains motionless and is left alone as the mother forages. As typical of ungulates, the calves are mobile within hours of birth. The calf develops quickly and is usually weaned by late summer. At six months it may weigh 265 pounds. Cows are mature by their second autumn and usually begin reproducing after three years. Bulls do not generally acquire cows and begin breeding until their fourth or fifth year.

    At one time gray wolves preyed on elk, and mountain lions still take a few annually. A pack of coyotes can kill a weakened elk or one immobilized by deep snow. Elk harbor parasites, including flukes, tapeworms and roundworms, lice, botflies, and mites. Chronic wasting disease (CWD)—a contagious neurological disease affecting the brains of deer, moose, and elk—is known in some Colorado elk populations. CWD primarily affects adult animals and typically results in dramatic behavioral changes. Infected elk are less social and may suffer from tremors, listlessness, nervousness, and excessive salivation. CWD’s common denominator is chronic weight loss, which ultimately leads to death.

    Human Interaction

    Where elk appeared in abundance, indigenous peoples hunted them for food, clothing, and tools. In Colorado, Navajo, Ute, Jicarilla Apache, Havasupai, Hopi, Zuni, and other peoples harvested elk in the southern Rocky Mountains and the Four Corners region.

    The pre-European period of abundance ended abruptly in the mid-nineteenth century. As white settlement and railroads moved westward, elk, bison, deer, and bighorn sheep were hunted to feed the growing western population. This reduced the elk population from an estimated 10 million to fewer than 100,000 in 1907. About one-third of those elk lived in the Yellowstone area and Canada.

    Colorado’s elk had a similar experience. The US Forest Service estimated that Colorado’s 1910 population contained 500 to 1,000 head of elk. The diminishing elk herds prompted Colorado to halt elk hunting throughout most of the state from 1903 to 1933. From 1912 to 1928, the Colorado Department of Game and Fish reintroduced 350 elk from Jackson Hole, Wyoming into fourteen areas. After elk populations rebounded, the state trapped elk from herds in southwest Colorado and transplanted them to other states to begin new herds.

    Return to Abundance

    Elk have been successfully restored to Colorado. With an estimated elk population of 280,000, the state hosts the largest elk population in North America. However, large elk populations can result in overgrazing that threatens ecosystem stability.

    State and federal wildlife officials use artificial strategies such as hunting and culling to manage elk populations. About 250,000 hunters pursue elk each year in Colorado, harvesting nearly 50,000. Culling, meanwhile, involves killing off fertile females when the elk population approaches a certain number. The need for such lethal management strategies shows that Colorado’s elk population has recovered.

    Rocky Mountain Elk are large mammals in the deer family. They live in Colorado’s forests. Each year, millions of people travel to Rocky Mountain National Park to see these animals. The state’s elk populations also attract hunters from around the globe.

    Ecology

    Colorado’s elk populations have changed over time. Elk moved across the Bering Strait from Asia at least 120,000 years ago. Elk arrived in northern Colorado about 8,000–10,000 years ago. They came to southern Colorado about 4,000–5,000 years ago. The elk population might have exceeded 10 million prior to European arrival in 1492.

    The North American elk is a gregarious grazer. Elk feed mostly on grasses instead of shrubs. Their current preference for forest cover is thought to be an innovation. Their herding behavior is typical of mammals that live in open country. Winter elk herds are large. They range from fifty to several hundred animals of both sexes. Winter herds disband as bulls move to summer range. Cow and calves follow bulls to summer range. Large winter herds break up into smaller bands.

    The crisp air of late September carries the bugling of bulls. This signals the beginning of the rut, or mating, season. Bugling is neither a challenge nor a threat. It is a release of tension built up during the bull’s seasonal changes. These changes include the shoulders and neck swelling and antlers sharpening. Bugling peaks in early October. The most aggressive bulls collect bands of five to fifteen cows. Another bull may challenge that authority through sparring, an antler-clashing battle for dominance.

    Gestation takes about 250 days. A single calf weighing about thirty-three pounds is born in June. The calf remains motionless and is left alone as the mother forages. The calves are mobile within hours of birth. The calf develops quickly and is usually weaned by late summer. At six months, it may weigh 265 pounds. Cows are mature by their second autumn. They usually begin reproducing after three years. Bulls do not generally acquire cows and begin breeding until their fourth or fifth year.

    At one time gray wolves preyed on elk. Mountain lions still take a few annually. A pack of coyotes can kill a weakened elk or one immobilized by deep snow. Chronic wasting disease (CWD) is a contagious disease affecting the brains of deer, moose, and elk. It can be found in some Colorado elk populations. CWD’s most common symptom is chronic weight loss. This leads to death.

    Human Interaction

    Where elk herds were large, indigenous peoples hunted them for food, clothing, and tools. In Colorado, Navajo, Ute, Jicarilla Apache, Havasupai, Hopi, Zuni, and other peoples harvested elk in the southern Rocky Mountains and the Four Corners region.

    As white settlement and railroads moved westward, elk, bison, deer, and bighorn sheep were hunted to feed the growing western population. This reduced the elk population from an estimated 10 million to fewer than 100,000 in 1907. About one-third of those elk lived in the Yellowstone area and Canada.

    Colorado’s elk had a similar experience. The US Forest Service estimated that Colorado’s 1910 population contained 500 to 1,000 head of elk. The shrinking elk herds prompted Colorado to halt elk hunting throughout most of the state from 1903 to 1933. From 1912 to 1928, the Colorado Department of Game and Fish reintroduced 350 elk from Jackson Hole, Wyoming into fourteen areas. After elk populations rebounded, the state trapped elk from herds in southwest Colorado and took them to other states to begin new herds.

    Return to Abundance

    Elk have been successfully restored to Colorado. With an estimated elk population of 280,000, the state hosts the largest elk population in North America. However, large elk populations can result in overgrazing that threatens ecosystem stability.

    State and federal wildlife officials use artificial strategies such as hunting and culling to manage elk populations. About 250,000 hunters pursue elk each year in Colorado, harvesting nearly 50,000. Culling, meanwhile, involves killing off fertile females when the elk population approaches a certain number. The need for such lethal management strategies shows that Colorado’s elk population has recovered.

    Rocky Mountain Elk are large mammals in the deer family. They live in Colorado’s forests. Each year, millions of people travel to Rocky Mountain National Park to see these animals. The state’s elk populations also attract hunters from around the globe.

    Ecology

    Colorado’s elk population has changed over time. Elk moved across the Bering Strait from Asia at least 120,000 years ago. Elk arrived in northern Colorado about 8,000–10,000 years ago. They came to southern Colorado about 4,000–5,000 years ago.

    The North American elk is a gregarious grazer. They feed on grasses.

    Winter elk herds are large. They range from fifty to several hundred animals of both sexes. Winter herds disband as bulls move to summer range. Cow and calves follow bulls. Large winter herds break up into smaller bands.

    In September, bulls begin to bugle. This begins the rut, or mating, season. Bugling is neither a challenge nor a threat. It is a release of tension built up during the bull’s seasonal changes. These changes include the shoulders and neck swelling and antlers sharpening. Bugling peaks in early October. The most aggressive bulls gather five to fifteen cows. Another bull may challenge that authority through sparring. That's an antler-clashing battle for dominance.

    Gestation takes about 250 days. A single calf weighing about thirty-three pounds is born in June. The calf remains motionless and is left alone as the mother eats. The calves can walk within hours of birth. The calf develops quickly. At six months, it may weigh 265 pounds. Cows are mature by their second autumn. They usually begin reproducing after three years. Bulls do not generally acquire cows and begin breeding until their fourth or fifth year.

    At one time, gray wolves ate elk. Mountain lions take some every year. A pack of coyotes can kill an elk stuck in deep snow. Chronic wasting disease (CWD) is a contagious disease affecting the brains of deer, moose, and elk. It can be found in some Colorado elk populations. CWD’s most common symptom is chronic weight loss. This leads to death.

    Human Interaction

    Where elk herds were large, native peoples hunted them for food, clothing, and tools. In Colorado, Navajo, Ute, and Hopi peoples hunted elk.

    As white settlement moved west, elk, bison, deer, and bighorn sheep were hunted to feed the growing population. This reduced the elk population from about 10 million to fewer than 100,000 in 1907. About one-third of those elk lived in the Yellowstone area and Canada.

    Colorado’s elk had a similar experience. The US Forest Service estimated that Colorado’s 1910 population was 500 to 1,000 head. Shrinking elk herds prompted Colorado to stop elk hunting throughout most of the state from 1903 to 1933. From 1912 to 1928, the Colorado Department of Game and Fish reintroduced 350 elk from Jackson Hole, Wyoming. After elk populations grew, the state trapped elk from herds in southwest Colorado. They took them to other states to begin new herds.

    Return to Abundance

    Elk have been brought back in Colorado. Colorado has an estimated elk population of 280,000.  That's the largest elk population in North America.

    Wildlife officials use strategies such as hunting and culling to manage elk populations. About 250,000 hunters pursue elk each year in Colorado, harvesting nearly 50,000. Culling involves killing off fertile females when the population reaches a certain number. The need for such strategies shows Colorado’s elk population has recovered.