Probation, restitution, and a ban of hunting and fishing licenses fell upon three Montana men.
Court documents say that Austin Peterson, Trey Juhnke, and Corbin Simmons crossed Yellowstone Park boundaries and shot a treed mountain lion, before transporting the carcass back to their vehicle.
The incident occurred in the northern section of the park, north of the Yellowstone River, on December 12, 2018.
Peterson, 20, was ordered to pay around$1,700 in restitution and fees, and must serve three years of unsupervised probation, during which he's banned from hunting, fishing, or trapping anywhere in the world.
The other two men, aged 20 and 19, were given similar sentences.
The illegal kill was originally reported by Peterson as having occurred in Montana north of the park, which interfered with quotas and took away a chance for another, law-abiding cougar hunter to harvest one in that area.
"I would like to express a sincere thank you to Montana Fish, Wildlife, and Parks, law enforcement officers at Yellowstone National Park, the National Park Service Investigative Services Branch, and the US Attorney's Office - District of Wyoming for being involved in this case," said Yellowstone National Park Chief Ranger Pete Webster. "Their thorough work spotlighted this egregious act and the consequences incurred for hunting illegally in Yellowstone National Park."
There are an estimated 20-31 adult cougars that live in the northern region of the park, and monitoring efforts since 2017 suggest a stable, sustainable population.