Colorado runner fought off mountain lion weeks before fatal attack on same trail
A local runner, Gary Messina, says he fought off an aggressive mountain lion on the Crosier Mountain trail on Nov. 11 and reported the incident days later, after which Colorado Parks and Wildlife posted (and later removed) warning signs. On New Year’s Day a woman was found dead on the same trail in a suspected mountain lion attack; hikers nearby scared off a lion, a physician found no pulse, and CPW officers tracked and euthanized two lions (searching for a possible third) while planning necropsies and lab tests — including checks for human DNA and diseases — to determine whether the cats were responsible.
📌 Key Facts
- A woman was found dead on the Crosier Mountain Trail in a suspected mountain lion attack; hikers on the trail spotted a mountain lion about 100 yards away around 12:15 p.m., scared it off by throwing rocks, and a physician among them checked the victim and found no pulse; the victim's identity has not been released.
- Colorado Parks and Wildlife (CPW) officers, Larimer County Sheriff’s deputies, Estes Park police, Glen Haven volunteer firefighters, a CPW biologist and houndsmen with tracking dogs responded to the scene.
- Responders located and euthanized two mountain lions at or near the scene and are searching for a possible third; nearby trails have been closed while the search continues.
- CPW will perform necropsies and laboratory testing on the euthanized cats — including checks for human DNA, abnormalities and neurological diseases such as rabies or avian influenza — to determine whether one or both animals were responsible for the attack.
- CPW officials say their policy is to euthanize wildlife involved in attacks on people to ensure public safety; it remains unknown whether a single lion or multiple animals attacked the woman.
- Trail runner Gary Messina reported a separate aggressive encounter on the same Crosier Mountain Trail on Nov. 11, 2025, saying a large mountain lion circled and tried to lunge at him; he fought it off by throwing objects and striking it with a stick, reported the incident days later, and said he believes that animal may be linked to the recent fatality.
- Officials and experts emphasized the rarity of fatal mountain lion attacks: Colorado’s last fatal mountain lion attack was in 1999, and authorities continue to investigate and provide guidance on avoiding and responding to mountain lion encounters.
📊 Relevant Data
Trophy hunting of mountain lions in Colorado, resulting in over 500 lions killed annually, destabilizes their social structures by targeting dominant males, allowing younger males to take over territories, which may increase conflicts with humans as these younger lions are less skilled at hunting traditional prey and more likely to target livestock or pets.
A Scientific Review of Mountain Lion Hunting and Its Effects — Animal Wellness Action and the Center for a Humane Economy
Colorado's mountain lion population is estimated at 3,800 to 4,400 independent-aged lions, with recent studies showing stable densities such as an average of 4.2 independent lions per 60 square miles in the Gunnison Basin during winters 2022-2024.
Mountain Lion Study Results | Colorado — Four Corners Chapter SCI
Increased outdoor recreation in Colorado's protected areas, driven by population growth and tourism, negatively impacts wildlife including mountain lions by disrupting habitats, increasing stress levels, and leading to more human-wildlife interactions.
Outdoor recreation in protected areas negatively impacts wildlife — Colorado State University SOURCE
Changing weather conditions due to climate change are driving mountain lion prey, such as deer, into urban areas for greener pastures, leading mountain lions to follow and increasing the likelihood of human encounters in Colorado.
What Tracking Mountain Lions Taught Me About Adaptability — Columbia Climate School
📰 Sources (5)
- Runner Gary Messina describes being rushed by a mountain lion on the Crosier Mountain trail on a dark morning in November, throwing his phone at the cat and ultimately striking it on the head with a stick to escape.
- Messina says the lion repeatedly circled behind him and tried to lunge as he backed away, and he reported the incident days later, after which officials posted then removed warning signs about mountain lions.
- Messina believes the mountain lion that attacked him may be the same animal suspected of killing the hiker on New Year’s Day, and experts note that if confirmed, the New Year’s death would be the fourth fatal mountain lion attack in North America in the past decade and the 30th since 1868.
- The article reiterates Colorado Parks and Wildlife’s actions after the fatality: officers killed two mountain lions and are searching for a possible third to test for rabies or other disease, and provides expert advice on how to avoid or respond to encounters.
- Runner Gary Messina reports he fought off an aggressive mountain lion on the same Crosier Mountain trail on Nov. 11, 2025, describing how it repeatedly tried to circle and lunge at him before he struck it with a stick and it fled.
- Messina reported the incident to Colorado Parks and Wildlife days later, prompting warning signs along Crosier Mountain trails that were later removed.
- Colorado Parks and Wildlife is now searching for a third mountain lion reported in the area in addition to the two already euthanized, and nearby trails remain closed while the hunt continues.
- Officials will conduct necropsies on the two killed mountain lions to determine whether one or both attacked the woman and whether they had neurological diseases such as rabies or avian flu.
- The article reiterates that Colorado’s last suspected fatal mountain lion encounter was in 1999 and details previous child deaths in 1997 and 1999 to underscore the rarity of such attacks.
- Colorado Parks and Wildlife says the last fatal mountain lion attack in Colorado occurred in 1999.
- Hikers on the Crosier Mountain trail saw a mountain lion about 100 yards from a person on the ground around 12:15 p.m. and scared it off by throwing rocks.
- One of the hikers was a physician who checked the victim and found no pulse.
- Responding agencies included CPW officers, Larimer County Sheriff’s deputies, Estes Park police and Glen Haven Area Volunteer Firefighters, assisted by a CPW biologist doing aerial deer surveys and houndsmen with tracking dogs.
- Officers located a mountain lion at the scene, shot it, then tracked and euthanized it; a second lion was found nearby and euthanized shortly thereafter.
- CPW stated that, under its policies, wildlife involved in attacks on humans must be euthanized to ensure public safety, and it remains unknown whether one or multiple lions were involved in the suspected attack.
- Hikers on the Crosier Mountain Trail spotted the victim and a mountain lion about 100 yards away around 12:15 p.m. and drove the lion off by throwing rocks.
- A physician among the hikers checked and found no pulse, confirming the woman was dead at the scene; her identity has not yet been released.
- Colorado Parks and Wildlife officers and dog teams tracked and euthanized two mountain lions in the area, though it is not yet clear if both were involved in the suspected attack.
- CPW spokeswoman Kara Van Hoose said there were signs consistent with a mountain lion attack but that the cause has not been definitively confirmed pending tests.
- CPW plans necropsies and lab testing of the euthanized lions, including checking for abnormalities, neurological disease such as rabies or avian influenza, and human DNA to confirm whether they were responsible.
- A local trail runner, Gary Messina, described a separate, aggressive encounter with a large mountain lion on the same trail about a month earlier in which the cat circled and tried to pounce on him before he drove it off with a stick and thrown objects.