►UPDATE 2/5:Mountain lion attack: Animal tests negative for rabies, rangers increase patrols and close park

►UPDATE 2/5:Mountain lion attack puts fear in some Fort Collins trail runners

►UPDATE 2/5:Trail runner suffocated mountain lion after attack west of Fort Collins

An unidentified man is recovering in a Fort Collins-area hospital after he killed a mountain lion in self-defense after the animal attacked him Monday afternoon at Horsetooth Mountain Park.

The man was running alone on the park's West Ridge Trail when he was attacked from behind, according to an initial Colorado Parks and Wildlife release. The animal was later identified as a juvenile mountain lion, possibly weighing about 80 pounds or more.

The man, whose name and place of residence have not been released, told authorities he heard something behind him on the trail and was attacked as he turned. He said he was bitten on his face and wrist but was able to fight and break free from the lion.

While defending himself, he told investigators that he killed the lion by suffocating it. The account was confirmed by investigators after examining the lion. The man sustained serious but not life-threatening injuries.

Wildlife officers found the mountain lion dead near where the incident took place while looking for items the runner asked them to find.

"The runner did everything he could to save his life,'' said Mark Leslie, CPW's Northeast Region manager. "In the event of a lion attack, you need to do anything in your power to fight back just as this gentleman did.''

The popular park west of Fort Collins was reopened Monday evening after closing during the investigation.

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Nick Clark is an avid ultrarunner from Fort Collins who ran to the top of Horsetooth Rock earlier Monday. He lives near the Larimer County-managed open space and said he's probably run in the park a "couple thousand times'' without seeing a mountain lion, though he has seen their tracks and deer they have killed.

"I honestly never think about being attacked by a mountain lion up there,'' he said. "We joke about it but maybe we shouldn't. We talk about we never see them but we assume we are being watched. They are generally very reclusive and there is plenty of deer up there for them to prey on. I'm much more concerned about rattlesnakes up there. They scare the crap out of me.''

While mountain lion attacks are extremely rare in Colorado, there have been at least two fatal attacks in Colorado since 1991.

In July 1997, 10-year-old Mark Miedema was killed by a mountain lion on the North Inlet Trail near Grand Lake on the west side of Rocky Mountain National Park in Grand County.

In 1991, a runner was killed by a lion while jogging above Clear Creek High School in Idaho Springs.

In October 1999, 3-year-old Jaryd Atadero was killed on the Big South Trail in the upper Poudre Canyon west of Fort Collins. The cause of his death has not been confirmed, though attack by mountain lion is one cause suspected by officials.

The last reported nonfatal attack was reported in June 2016 in Pitkin County.

CPW said fewer than 20 fatal mountain lion attacks on humans have been reported in North America over the past 100 years. Since 1990, 16 people have been injured from mountain lion attacks in Colorado.

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Mountain lions are known to be active in and around Fort Collins. CPW shot and killed a mountain lion north of Wellington in November 2017 after it killed goats and alpacas in the area.

Runners and hikers should be aware of the potential presence of mountain lions when recreating in the foothills west of Fort Collins. Here are a few things to know about the predators:

How to tell if it's a mountain lion

Mountain lions, also known as cougars, are much bigger than bobcats or the vast majority of household pets: 5 to 7 feet from nose to tail tip for females, 6 to 8 feet for males, according to the Mountain Lion Foundation. Their tails measure almost one-third the length of their bodies. They are generally tan all over, but mountain lion kittens have spots. You can distinguish mountain lion kittens from bobcats by tail length — bobcats have very short tails.

Obviously, you shouldn't get close enough to a mountain lion to measure it, so another way to tell if you spotted a mountain lion is to inspect visible tracks in the area. A cougar's paw print has a distinctive "M" shape, with three lobes on the bottom compared to two lobes on a dog's paw print.

How to keep yourself and your pets safe

Mountain lion attacks on humans are rare. The best way to protect yourself is to keep your distance and not approach wildlife. Use the rule of thumb: If the animal is small enough to cover with your thumb, you're at a safe distance.

If you find yourself too close to a mountain lion, CPW suggests you back slowly away if you can do so safely. Raise your arms and open your jacket if you have one. Hold small children in your arms, if you have a youngster with you. Speak calmly to the lion in a firm tone of voice.

If the lion approaches you or is acting aggressive, wave your arms and throw stones or whatever you can reach without turning around or crouching. In the unlikely event of a cougar attack, fight back with whatever you have on hand and try to stay upright.

According to the CPW website, "people have fought back with rocks, sticks, caps or jackets, garden tools and their bare hands successfully."

As for keeping your pets safe, keep them on a leash. Don't feed your pets outside, and keep them indoors at night if you can. If you keep your pet outdoors, a kennel with a secure top is a good idea because mountain lions can climb fences.

How to report a sighting

If you think you saw a mountain lion in an urban or unsafe area, report the sighting to CPW's Northeast Region Office at 303-291-7227 (not Larimer Humane Society). Reporting sightings helps CPW determine an animal's whereabouts and what, if anything, to do about it.

Cougars generally avoid people in pursuit of deer, but if a mountain lion in an area seems to pose a threat to people or livestock, CPW might intervene.

This developing story will be updated as additional details become available.

Coloradoan reporters Miles Blumhardt and Jacy Marmaduke contributed to this report.

Coloradoan editor Eric Larsen can be reached at ericlarsen@coloradoan.com or 970-224-7745. To support local journalism in Fort Collins and help the Coloradoan reach its goal of reaching 20,000 digital subscribers by the end of 2020, visit offers.coloradoan.com/specialoffer.