John Vomastic saw that three of the cats were around his cabin on March 23. Security video shows them walking around his property, with one looking up into the window.
It happened a little after sunset.
"One of the three lions did a bit of exploring. He walked over to my PV solar array and looked down the mountainside," Vomastic said.
"I was watching him from the window. I made some noise to get his attention. He turned and walked toward the window. When he raised himself and put his front paws on the window, I got a bit scared."
Despite being frightened, he managed to get a picture of the mountain lion as it looked curiously through the glass.
"The only thing that was protecting me from that big cat was a piece of glass," he said.
He then began to fear it would break through the window, so he took a few steps back. Fortunately, a car coming up on the road scared the animals away.
Vomastic said he has seen many wild animals near his home, including deer, bobcats and bears.
But none have scared him as much as the mountain lions did.
"It was a bit unsettling," he said.
Michael Seraphin of Colorado Parks and Wildlife said that the mountainous terrain is ideal for mountain lions.
"[There's] plenty of open space, no other houses in view, a nice valley, a place where you'd be likely to find deer," he said.
He recommends that those who encounter mountain lions to stand up tall and look as big as possible.
"Put your arms up. If you have a coat, open it up. Slowly back away. If you are with others, form a group."