Mountain Lions and the Front Range
Colorado is home to an estimated 3,800 to 4,400 adult mountain lions. Known also as cougars or pumas, they range across the western two-thirds of the state, with the highest densities in foothill canyons, mesa country, and areas of dense oak brush, pinyon pine, and juniper. The Front Range foothills — from Larimer County down through Jefferson, Boulder, and Douglas counties — fall squarely within established mountain lion range.
Mountain lions are naturally elusive and rarely seen. Most Front Range residents spend years in lion country without a sighting. That doesn't mean lions aren't nearby. Trail cameras in foothills communities regularly capture lion activity in areas where people hike, run, and let their dogs off-leash. The animal's primary food source is deer, and anywhere deer congregate — including suburban greenbelts and open space corridors — mountain lions may follow.
Signs of Mountain Lion Activity
Because mountain lions are seldom seen directly, knowing the signs of their presence is useful. Look for:
- Deer carcasses covered with dirt, leaves, or debris — mountain lions cache their kills and return to feed over several days. If you find a covered deer carcass, leave the area and report it to CPW. Do not investigate further.
- Large tracks — round, about 3–4 inches wide, no visible claw marks (lions retract their claws when walking), with a distinctive asymmetrical heel pad.
- Scrapes — small mounded piles of dirt or debris used by lions to mark territory.
- Missing or injured pets — small dogs, cats, and other pets are vulnerable, especially at dawn and dusk.
Protecting Pets and Livestock
Pets left unattended outside — especially at dawn and dusk when lions are most active — are at real risk in foothills communities. Mountain lions do not distinguish between a deer and a small dog. CPW's guidance for pet owners in lion country:
- Keep pets on a leash when outdoors. A roaming dog can surprise a lion or follow a scent directly toward one.
- Bring pets inside at night. If they must stay outside, use a fully enclosed kennel with a secure roof.
- Do not leave pet food outside — it attracts smaller animals that lions prey on, which in turn attracts lions.
- Be especially alert during dawn and dusk hours.
- Do not leave small children unattended outside in foothills areas, particularly near natural areas or open space.
Livestock owners should house animals in enclosed sheds or barns at night. Close all outbuilding doors — curious lions will explore open structures. CPW has a compensation program for documented livestock losses to mountain lions.
Reducing Lion Attractants in Your Yard
Mountain lions follow deer. Anything that draws deer to your property increases the likelihood of lion activity nearby. Avoid:
- Planting deer-preferred ornamentals like hostas, tulips, roses, and arborvitae in low-fenced areas
- Leaving bird feeders that drop seed to the ground, which deer forage on
- Dense shrub plantings close to the house that provide cover
Reducing dense vegetation near the home and eliminating hiding spots like thick brush piles and low-hanging branches can make your property less attractive as a travel corridor.
If You Encounter a Mountain Lion
Mountain lion encounters are rare. Attacks on humans are rarer still — CPW documents fewer than 25 attacks on people in Colorado since 1990. Most lions, when encountered, will retreat. If you come upon a lion:
- Stay calm. Do not run. Running triggers the predator's chase instinct.
- Make yourself appear large. Raise your arms, open your jacket, stand tall. Pick up small children immediately without crouching or turning away.
- Speak firmly and loudly. Maintain eye contact. Talk to the lion in a firm, steady voice.
- Back away slowly while keeping the lion in sight. Give it a clear escape route.
- Do not approach it, especially if it is feeding, crouching, or with young.
- If attacked, fight back. Unlike with grizzly bears, playing dead is not recommended. Use anything available — trekking poles, rocks, your hands — to defend yourself aggressively.
When and How to Report a Mountain Lion
Contact Colorado Parks and Wildlife if a lion:
- Is seen in or around a residential area during daytime hours
- Has killed livestock or pets
- Shows no fear of humans or approaches people
- Has cached a kill near a home, trail, or recreational area
CPW offices are open Monday through Friday, 8 a.m. to 5 p.m. The Northeast Region office covering the Denver metro and Front Range foothills can be reached at (303) 291-7227. For emergencies after hours, call 911 or the Colorado State Patrol. Mountain lions cannot legally be killed when they are only causing damage to personal property — lethal action is only permitted when necessary to prevent death or injury to people or livestock.
Sources & Further Reading
Related guides
Frequently asked questions
How common are mountain lion sightings in Front Range neighborhoods?
Sightings are uncommon but not rare in foothills communities. Lions are naturally secretive and most activity goes undetected. Trail cameras in areas like Evergreen, Morrison, and the Boulder foothills regularly capture lion movement. CPW receives thousands of reports statewide each year.
Are mountain lions more active at certain times of year?
Mountain lions are active year-round. They are most commonly seen in winter when snow reveals tracks and deer concentrate at lower elevations, bringing lions with them. Young lions dispersing from their mother's territory — typically in fall — are the most likely to behave unexpectedly near people.
Can I legally kill a mountain lion that threatens my pets?
No — Colorado law does not allow lethal action against a mountain lion for threatening or killing pets. Lethal action is only permitted when necessary to prevent death or injury to people or livestock. Contact CPW for guidance if a lion is repeatedly visiting your property or has killed livestock.
What should I do if a lion kills one of my chickens or goats?
Secure remaining animals immediately and contact your local CPW office. CPW has a livestock damage compensation program. They can also provide guidance on exclusion fencing and deterrents specific to your property.
Does CPW track mountain lions in the Front Range?
CPW conducts ongoing research on mountain lion populations, including GPS collar studies in some areas. Individual homeowners can report sightings to their local CPW office, which adds to the agency's understanding of lion movement patterns near communities.