That's what I used to fish for at the ends of the wings dikes on the Mississippi. Like Dan said, Great fight on medium-heavy bass tackle - especially when they're down deep and have a bit of current to work with! I've never eaten one - strictly catch and release for me - but I hear that they are the best tasting of the catfish, too!
Those things get much bigger than that. I've caught a few 40 pounders myself, but have seen some close to 100. Here is the world record....123 pounds. Supposedly caught by a crappie fisherman with a minnow with 12 pound test (not very believable, but I guess possible)