Rangerman40 wrote:
70-25-80... get off in Rawlins and Wind your way up toward the Tetons on 287 to 26 through the Wind River Indian Reservation. Hop on 191 in the Tetons and you are golden all the way to West Yellowstone. Fuel stops are a little sporadic once you get off 80 till you hit Dubois. And I believe there are no fuel stations between Dubois and Moran if I remember correctly. This is the scenic route... you could come in the backside through Utah and Idaho taking 80-15-20.
Agree with Rangerman's first route as we have done that a number of times. North of Rawlins there is a gas station (don't know whether they have diesel) at Muddy Gap and several gas stations in Lander. Lander is a significant size town so diesel should be available. Dubois is much smaller so fueling in Lander would be a wise precaution. The next fuel that I can recall is at Colter Bay just north of Moran Junction. When driving through Yellowstone to West Yellowstone fuel is available at Grant Village and Old Faithful. Between Dubois and Moran Junction you will go over the Togwotee Pass. It's a gradual climb and descent, so you should be fine. A beautiful drive and a good chance of snow still being at the top of the pass in June. Good views of the beautiful Teton Range going down the west side.
If you want a more level route, stay on I80 to Rock Springs then take 191 north to Hoback Junction and continue north to Jackson and through Grand Teton NP to Yellowstone. Fuel available in rock Springs, Boulder, Pinedale, Jackson and possibly more.
Personally, I wouldn't stay on I80 all the way to I15 and then up route 20 as it's too much out of the way.