Lander, Wyoming -- Sleeping Bear RV Park
If you're looking for an RV Park with excellent bathrooms, I recommend this one. We stayed in Lander for two nights -- the park is a typical RV Park -- close sites -- some with good views of Lander because the park is a short distance out of town on a hill that overlooks the town. They have about 6 complete bathrooms with shower stall, sink, toilet, so you have complete privacy and plenty of hot water. After Colter BAy where we had to pay $4.50 for public showers, this was very very pleasant.
If showers are not your thing, then Sink Canyon State Park looks like an excellent place to stay -- scenic -- We took a short walk there to see the river. It's unusual because the river flows along and then completely disappears as the water sinks into the rock and underground caverns. A quarter mile downstream the river resurfaces and there you can see hundreds of trout feeding (no fishing allowed at this point.)