One area that I really enjoy is the Narrows in the Bridger-Tetons. It's
outside Cora, Wyoming, about an hour south of Jackson Hole. Twin lakes.
Sand beach. High altitude. Trailhead. Nice trout. Water on site. No
hookups. Moose, wolverines, elk prong-horned antelope, etc...

The lakes are small and used to be no motor, but that changed. It's
still a great place to bob around in a float tube and pretend to fish.
There _is_  about an 8 (?) mile trek of washboard to get back there, but
my '85 never had any problem with it.

The closest town is Pinedale, which has groceries, hardware, a couple of
gas stations, a (small) bookstore, a couple of restaurants, and an
expensive outfitter.

And a YMMV disclaimer because I didn't get there this summer. Funny
things can happen in 2 years.

Joan
SW FL along the gulf
'82 Vanagon (ex)
'85 Westy GL
'95 Eurobago
currently haggling for a '91 Westy