When I left Yellowstone I went through West Yellowstone and took I-15 South down to Salt Lake City. I know there was a campground just North of the Idaho - Utah border but it was just a place to park your RV and sleep. I am not sure if it had electrcity or water because me and my friends sleep in a tent.

I do know that there is another route that heads south from Jackson but I was toild there is a very scary pass you have to cross.

Last summer my husband rode LatoJa (Logan, UT to Jackson, WY in a day on a bicycle - 206 miles) and the route followed was very pretty. Logan to Preston, ID to Montpelier, ID to Afton, WY to Alpine, WY and turn right to follow the Snake River into Jackson. I remember seeing USFS camping along river. Take a look at http://www.lotojaclassic.com/ and navigate to course info, course map to view the route. The red line is what the bikes followed and the blue is what I followed as his support vehicle. Definitely follow the red route. Enjoy!

We went to Yellowstone last fall from the opposite direction and someone had sent us to a website with a wonderful writeup and maps telling you all the different routes and what to take in different vehicles. http://www.rvcruzer.com/ystonervroutes.php I'm sure this will help you. Enjoy the trip!

Thank you all very much for your information, it will be most helpful in our planning.

Fred, thanks for sharing that site. I book marked it for future use. Yellowstone is on our short list of places to go.

Fred, that site is terrific and exactly what I was looking for.  That fellow really put a lot of detail and experience into documenting his Yellowstone travels.  I'll have a copy of it in my truck.  Thanks very much.  Marty