There's a reservoir nearby, never seen it, but saw a sign for it. Never even drove through the campground, but there is a restaurant nearby that is supposed to have decent food.
Don't think you can go wrong with either place. Don't believe you can go wrong with any campgrounds in the Big Horn mountains; at least never heard of seen something bad.
If you go to Southfork, keep us informed. I was thinking of heading over that way again this summer and would like to try a different campground.