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A mountain trail in northern Colorado will remain closed for the rest of the week after a mountain lion attacked an unarmed trail runner, who killed the animal with his bare hands, authorities said Tuesday.

The runner, who hasn't been identified, was attacked on the West Ridge Trail at Horsetooth Mountain Open Space near Fort Collins on Monday, the Colorado Parks and Wildlife agency said.

The state wildlife department said in a statement Tuesday that it had confirmed the man's account "that he was able to suffocate the animal while defending himself from the attack." It said the man was able to make his way to a nearby hospital, where he was being treated for serious but non-life-threatening puncture wounds to his arms, legs and back.

The man "didn't have any weapons," Ty Petersburg, area wildlife manager for the wildlife agency, told NBC affiliate KUSA of Denver.

"He was really creative," Petersburg said. "He used his hands, feet — things that were around him — and really it was just a fight for survival."

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Authorities described the animal only as a mountain lion that was less than a year old, saying they couldn't determine its weight or precise age because other animals had started to eat it by the time they found its body near some of the man's possessions.

The cat tested negative for rabies, "which is very welcome news," the wildlife agency said.

Petersburg said the man followed the state guidelines when the cat confronted him: He put his hands in the air, made a lot of noise and stood his ground.

But "probably what happened here is that the lion had an instinct triggered," Petersburg told KUSA. "It wasn't so much tracking a human or keying in on a human. It just had an instinct triggered like it would if you were to roll a ball of yarn across the ground for a cat."

The state wildlife department and Larimer County rangers initially reopened the trail area on Monday night. But they again closed all trails at the open space on Tuesday after rangers spotted more mountain lion activity in the area, the state agency said. The closing will be reassessed on Friday, it said.

Colorado Gov. Jared Polis joked in a statement: "Don't mess with Colorado trail runners."

"A runner near Fort Collins killed an attacking mountain lion with his bare hands," Polis said Tuesday. "Don't try this yourself on purpose, as it is likely to end poorly for you."

Petersburg said it was the most incredible story he'd been a part of in 17 years with the department.

"To be able to see a man face adversity like that and come out on the other side is pretty amazing," he said.

State officials reiterated on Tuesday that mountain lion attacks on people are extremely rare. The state's last attack was reported in June 2016, when a 5-year-old boy was seriously injured outside his home in Pitkin County, west of Denver. The boy survived.