We just completed our 1,900 mile family trip from Portland, Oregon to Yellowstone and back. We took the 'northern' route (I-84, I-90, etc.) on the way out and returned via Teton. The trip map is located below.
Trip out: Portland, Hayden Lake, Idaho (Silverwood Theme Park), West Yellowstone.
Yellowstone: 5 days of wonder
Trip back: Teton National Park (Colter Bay RV Park), Craters of the Moon (Arco, ID), Unity Lake State Park (Unity, OR), John Day Fossil Beds Sheep Rock Unit, Kah-Nee-Ta Hot Springs Resort (Warm Springs, OR)
Route lesson learned: Take Hwy 191 and 26 from Jackson instead of Teton Pass like what typical GPS and Google recommends. The pass is 12% grade over Teton instead of the typical 5-6% max just staying on highway 26. We started the climb and decided to turn around and just stay on 26. Staying on 26 only adds 20 miles, much less stress on the RV and a beautiful view of the Snake River.
Best MPG: 10.41 MPG. Worst: 8.4 MPG.
Gas prices from 3.33/gallon (Idaho) to 3.63 at West Yellowstone
Weather: Perfect for the entire trip. Highest temps were 92 degrees at Craters of the Moon. Yellowstone high was 85. Haze/smoke noted in Idaho near Boise and in Teton in the afternoon.
Campgrounds: (1) Silverwood Theme Park RV Campground (Athol, ID), (2) Rustic Wagon RV Park (West Yellowstone), (3) Colter Bay RV Park (Grand Teton National Park), (4) Unity Lake State Park (Unity, Oregon), (5) Kah-Nee-Ta Hot Springs Resort (Warm Springs, Oregon)
Car Rental @ Yellowstone: Big Sky Car Rental @ $49/day
Most Expensive Campsite: Colter Bay in Grand Teton NP ($61.56)
Least Expensive Campsite: Craters of the Moon ($10)
RV Issues Encountered: Check Engine light came on @ last 500 miles of trip. Trouble code determined to be solenoid for EVAP/charcoal canister. Otherwise, performed flawlessly.
Much more detail of the trip, including photos and campground information are available on our family website: Photo Albums