I don't know about black ones, but there are certainly the regular golden variety. I saw one in Chilton County in 2007. middle of the day. i entered the woods and it was on a low tree limb about 30 yards away. it ran down the tree and away from me down a deer trail. this was open woods in the winter. I threw the gun up and watched him run off for 100 yards. 100% confident in what animal it was. much larger than a bobcat. long tail. just a mountain lion. nothing else. I had caught a quick glimpse of it in the truck headlights a few nights before when I went to the farm to feed horses. checked the ditch and saw prints in the mud. obvious large cat prints. no claws. deep enough to show if they were out.

I remember going to Tigers for Tomorrow several years ago. They have a pen with mountain lions in it. they said they have come to feed them in the morning and found mountain lion track on the OUTSIDE of the pen... where the wild ones have come to visit. they claim to have heard the captive and the wild ones calling to each other across the valley.

I used to know a guy back home in South Carolina that shot one. The state said they didn't exist. He swore one was eating his goats. The game warden said it wasn't possible. He shot it in his back yard a couple of weeks later with his wife filming it. He handed over the video and the dead cat to the game warden. They still swear they don't exist. He said that he got the impression that they don't want them to there... at least not public. There aren't many, and they are afraid people will freak out if they think there is a problem. There are so few that it's easier to just explain each single one away with a better story.
I don't know about all of that.... but I know 100% that I saw one in Chilton county and had plenty of time to watch it run off starting at 30 yards.

-Keith