I've been in Colorado for five seasons and just had my first mountain lion encounter.
I had packed in my solo camp for deer and elk about a mile and a half to timberline on Saturday morning in the dark. After chasing elk out three times over the first two days, I spent Monday afternoon stalking a very large, symmetrical four-point buck.
I often leave my pistol, a single-action .45, in the tent as I have always felt it creates a bit of noise (and I'm already terrible at closing to within recurve range on foot). That particular evening I chose to carry it, however, and I'm glad I did.
I returned to the park below camp about an hour after dark and steadily climbed the hill. I turned my headlamp back to high beam as I entered the trees close to camp, and was immediately startled by a large pair of evil-looking eyes staring down on me from just below where my camp was set up, maybe 60 yards away. I'd always dreaded the day that I would inevitably run into a mountain lion, and the time was now.
I've never had an adrenaline surge like I had at that moment and I charged up the hill toward it with my gun out, intending to play "tough guy" and scare it off until I realized that it probably wasn't smart to chance an even closer encounter with the cat. I began saying things to the cat that can't be repeated, but suffice it to say my mother would not have been pleased with my choice of language.
Fortunately, the cat slinked away and I never saw it again. I hope I never do.
What do you do to combat the likelihood of running into cats (is there a way?) and what do you carry just in case? A single-action .45 is felt a bit inadequate in the moment.