From the size you describe, it's the big one with a long tail. The only other one with a footprint coming close to a cougar is a Lynx, and I'd bet on a Cougar before a Lynx.
Carnivore track sizes Lynx are pretty small. I have seen Bobcat. But this is close to what the print looked like:
About 4.5-5" wide, 4 toes, no claws, and I never looked at the heel pad because the print was so large and I kinda said something I can not repeat.
Oh Joy! I am not worried about me or anyone else, but Luna would defiantly take it on. And I am only worried about her.
I was hoping, but can't deny the facts. We got us a Mountain Lion hanging around!