Yeah, the cougar was really wild! I grew up in Los Angeles, where they are fairly numerous, but it is rare to see one in daylight, and even researchers studying them can go days without seeing one.
Although we have a tiny building lot in Taos County, New Mexico, next to the Colorado border, and a woman near there told us that she sees cougars trekking across the high plain on a regular basis. Of course, in that area, most of the brush isn't tall enough to conceal them.
The butchered animal was in a turnout next to our little bridge, over the Calfkiller River, but there's no way it could have ended up in the river unless someone physically threw it in. Then again, who knows?
And, although I didn't get close enough to smell it, it was clearly fresh, and looked as though it might even have been smoked.
It was gone when I checked it the following day. My guess is that someone stopped there in a pickup, with the tailgate down, and it fell out when they accelerated out of there.