If you're refurring to I-90, that will bring you to the north entrance to Yellowstone where we stayed a few years ago outside a town called Gardinier. There is 3 or 4 RV parks in that area all within 15 miles of the north entrance. Check your Woodalls or Trailer Like Directory. Next time there, I plan to enter from the east side in the Jackson Hole area as I've been told it's much closer the heart of everything going on in the park. Enjoy your trip!
Jackson Hole is actually to the South, Cody is to the east. Although I guess it really doesn't matter, as long as you get there.
2007 Forester 2941DS
2005 KIA Spectra
Zamboni, Long Haired Mini Dachshund
You can have my RV, when you pry my cold dead fingers from the Steering Wheel
I would enter from Gardiner. The beartooth hwy is one of the most beautiful highways in the lower 48 states but without a trailer would be my choice. We have stayed in West Yellowstone at Grizzly RV Resort and its very nice, and also in Fishing Bridge near lake Yellowstone. FB has full-hookups but may be booked for the summer.
I'd highly suggest staying in the park unless you can't live without full hookups. You will waste too much time driving back and forth especially in the crowded peak summer months. If I were to stay outside the park I'd be heading to West Yellowstone, just outside the west gate and centrally located in relation to Yellowstone.
2006 Silverado 2500hd duramax 4x4 - with a few mods
Here's my 2cts. We've been to Yellowstone 3 times in the last several years from Southern Kentucky. We went over Beartooth the first time in a small motorhome and it was a thrill; especially at night with huge banks of snow/ice on both sides of the road; cars parked on the pulloffs covered with ice. Since then I've come in on 89 and simply drive down to Grizzly RV Park in West Yellowstone as a base and rent a car locally which we use to travel everywhere from the Tetons, Jackson and into Idaho. After that first trip we moved up to a larger MH also.
We went from Mich in2010 out I80 back I90. I 90 is a much easier drive. Personally, I just don't get get the "where to stay" issue. Wherever you stay, it will become your "base" to see all the park you can. So if you stay in the north, you will drive to see the south the east and the west sides of the park. it all equals out in the end, unless there is one side of the park you don't intend to visit. We did not have "hours of travel time". Okay, we did. The same amount everyone else has as they make their way from side to side in YSP. We stayed at Grizzly west YS and I highly recommend it. I'm a major penny pincher but i can't drive 1500 miles and not know I'm going to have acceptable accomodations. It was worth every penny!!!