Mountain lions certainly do show up in practically every county west of I-35 at some time or other.The Trans Pecos is filled with them.
Black ones? I've not seen one. However..........
Bobcats can [whether intentional or not,I don't know ] fluff their hair in such a way as to leave only the tips of the hair showing,and they "turn black".I've seen it on two different occasions myself.
Possibly lions can do the same.One ran across the road in front of me just before sunrise thirty-some years ago in Young County and it looked black , or at least dark , under those light conditions.
