Have seen otters on lavon, Pat Mayse, and crockett. Have heard of them in the sabine around Carthage also. I think they are everywhere at least from dfw east.

My uncle traps/removes otters and beavers pretty regularly. He has a decent market for otters, but the guy he deals with wants the whole thing and will skin it out, apparently there is no margin for error when it comes to skinning otters.

As far as removal, beavers and otters are the aquatic equivalent of wild pigs. If you stay on them, you can keep them in check if you are only monitoring 1 or 2 ponds, but left unchecked they will wreak havoc.

Speaking of beavers...