BangPop and fishnut pretty much nailed it. I lived on the Gros Ventre in Kelly for 10yrs. Personally it's a 9' 4wt stream IMO. Black and cinnamon ants will catch a lot of fish on the GV and there are a bunch of sculpins in there.
There are some good lakes up in the GV drainage, Crystal Cr is good above Red Rock Ranch too.
