I used to use leeches for smallmouth and walleye back in WI.
I tried to buy some down here and was told that the sale of leeches is forbidden. Something to do with introducing a species not common to the local waters.
Now I've heard from several sources that they have witnessed leeches in the rivers down here. I don't know what the reasoning behind the ban is, but I can't find them for sale around Mountain Home.