Colorado wildlife officials are investigating the state’s first fatal mountain lion attack in more than 25 years after a woman was found dead on the Crosier Mountain Trail near Glen Haven on New Year’s Day. The incident is being treated as a suspected mountain lion attack pending confirmation from the Larimer County Coroner’s Office, according to Colorado Parks and Wildlife (CPW).

Two hikers discovered the woman shortly after 12:15 p.m. on January 1. They reported seeing a mountain lion lying partially over her body before throwing rocks to scare the animal away. One of the hikers, a physician, checked for a pulse but found none. The victim’s identity has not yet been released.

CPW officers tracked and euthanized two mountain lions in the area, following agency policy requiring the removal of animals involved in attacks on humans. A third lion believed to be nearby is still being sought by wildlife officers. DNA testing and necropsies will determine whether one or both of the euthanized lions were responsible.

The attack occurred on a remote section of the Crosier Mountain Trail, an area where several recent lion encounters have been reported. In November, a runner fought off a mountain lion on the same trail after it rushed him in the dark, an incident he described as a life‑threatening struggle. Other hikers have also reported unnerving encounters in recent weeks, including one couple who said they believed they were nearly attacked by the same lion or lions involved in the fatal incident.

Fatal mountain lion attacks in Colorado are extremely rare. The last confirmed death occurred in 1999, when 3‑year‑old Jaryd Atadero went missing during a hike in Larimer County. Although sightings and non‑fatal encounters occur periodically, CPW emphasizes that lions generally avoid humans and that deadly attacks are uncommon.

Trail closures remain in effect around Glen Haven and the Crosier Mountain area as the investigation continues. CPW is urging hikers to avoid the region and to remain alert on nearby trails. Officials also reiterated standard safety guidance: stay in groups, keep children close, make noise, and never run if a mountain lion is encountered.

The Larimer County Sheriff’s Office, CPW, and the coroner are jointly investigating. Additional details, including the victim’s identity and the coroner’s findings, are expected in the coming days.