by North Forty News Staff | NorthFortyNews.com
Trail closures follow rare attack near Crosier Mountain
Trails near Crosier Mountain and Glen Haven in unincorporated Larimer County have been temporarily closed following a suspected fatal mountain lion attack reported Jan. 1, prompting a multi-agency response and an ongoing investigation by Colorado Parks and Wildlife (CPW).
According to CPW, around 12:15 p.m., hikers reported seeing a mountain lion near a person lying on the ground on the Crosier Mountain trail. Witnesses approached from roughly 100 yards away and threw rocks to scare the animal off. They then attempted to assist the adult woman but were unable to detect a pulse.
CPW officers, Larimer County Sheriff’s Office deputies, Estes Park Police Department, and Glen Haven Area Volunteer Fire Department responded and conducted an extensive search for mountain lions in the area. A CPW biologist assisting with aerial deer surveys helped spot animals and transport personnel, while houndsmen used dogs to track lion scent.
Officers located one mountain lion at the scene; after it ran, it was tracked and euthanized. A second mountain lion found nearby was also euthanized. Officials said it is not yet known whether one or multiple animals were involved. Under CPW policy, wildlife involved in attacks on humans must be euthanized to protect public safety.
CPW pathologists will perform necropsies on the animals to check for abnormalities and diseases, including rabies and avian influenza. The Larimer County Coroner will release the victim’s identity and the official cause of death.
Mountain lion attacks on humans are rare in Colorado. CPW reports 28 attacks statewide since 1990, with the last fatal attack occurring in 1999.
In response to the incident, the U.S. Forest Service has closed the following trailheads within the Arapaho and Roosevelt National Forests and Pawnee National Grassland, effective Jan. 2, 2026, until further notice:
– Garden Gate Trailhead (Crosier Mountain Trail 931)
– Gravel Pit/Rainbow Trailhead (Crosier Mountain Trail/Rainbow Trail 981)
– Piper Meadows/Glen Haven Trailhead (parking area near the Glen Haven Volunteer Fire Department)
Along the Front Range and in Larimer County, CPW reminds residents that wildlife encounters are more common in winter as mountain lions follow deer and elk to lower elevations. If a mountain lion is encountered, people should make noise, hold objects overhead to appear larger, slowly back away, and keep pets leashed and away from wildlife.
For ongoing updates and safety information, visit the CPW news page at https://cpw.state.co.us/news.
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Source: Colorado Parks and Wildlife; U.S. Forest Service – Arapaho & Roosevelt National Forests and Pawnee National Grassland
