Love how most of the areas that are dispersed sites are free! Many to choose from and right on the river!
Firstly, dont follow your gps to the coordinates given here, if you follow it to the point on google maps you'll end up at one of the highest points in that valley (and you'll see my newly made "night one" site. If you want the site in the pictures, which was fairly quiet other than a few people checking if it was open, take the first right after the bridge and follow the trail down. Lots of trails, more people near the river but if you're into desert camping and want seclusion you'll want to get into the hills (towards google maps point) but hang a right at the top of the trail. Overall, pretty great place to getaway.
If you enjoy Fly Fishing for Brown Trout, this place is awesome. There is dispersed camping all along the river below the dam. It is very rugged, but there are amenities for camping. Just follow Owyhee Lake Rd along the river and you will find spaces to set up your tent or RV. It is a bit deserty, so beware of snakes. You will find quite a few places before the tunnel. There are some places for RVs after the tunnel as well. But there are quite a few places to set up tents. There are some J-Jons along the stretch of river with camping spots near them.