North of Idaho Falls, US-20 climbs into Island Park and the lodgepole goes flat along the Henrys Fork. People come up here to fish the Henrys Fork. The basin stays high and cold, snow can hang in the trees into May, and the river runs clear through the flats once the road is open. Behind Henrys Lake, Sawtell Peak sits on the Continental Divide like a wall, and at Box Canyon the river bends hard and a rim trail walks the drop.
You come at Yellowstone from this side when the west entrance road is open. The park interior and its campgrounds belong on the Yellowstone campervan page. You sleep on this side of the line and go in for the day.
Henrys Lake State Park is the full-hookup night, with that peak on the far shore. In summer, lock a serviced site through Idaho Parks and Recreation before you book the van. The park has 83 of them.
Buffalo Campground is the big Forest Service loop in the lodgepole on this stretch of US-20, and the Forest Service takes reservations from late May through early September. Box Canyon sits right on the river and is first-come only and takes RVs up to 40 feet. Take it when the reservable loops are already gone and you are willing to roll in without a confirmation. Even if you sleep at Buffalo or Henrys Lake, the Box Canyon rim is the walk, with the river down in the slot and the trail along the edge.
Off the Mesa Falls Scenic Byway, Upper Mesa Falls drops 110 feet through a basalt notch, with mist coming up off Lower Mesa Falls a mile downstream. Grandview is a small campground next to that water if you want to overnight beside it.
Outside the fee season, those Forest Service pads go first-come and free when the road is clear, with no water or toilets.
Craters of the Moon
West of Idaho Falls the sagebrush turns black. Cinder cones rise off the plain, and the Spatter Cones sit on a short boardwalk through the cinders. The Caves Trail is the one everyone does, ducking into lava-tube mouths and dropping you back out onto the cinders.
Lava Flow Campground is the overnight inside the monument, with no hookups. It is first-come only, with no reservations. The loop road closes to vehicles in November and reopens in April or May, as of September 2026, and once the road is closed, a free permit lets you hike in and snow-camp. The monument sits about 84 miles from Idaho Falls on US-20/26/93.
Teton Valley on the Idaho side
ID-33 runs into Teton Valley with the Big Hole Mountains behind the grain elevators in Driggs. The Teton River folds into oxbows you can see from the highway. Grand Targhee sits up the Idaho side of the range.
You overnight in the valley on the Idaho side. Forest Service loops around Victor take reservations from late May through early September.
Mike Harris sits about five miles southeast of Victor on ID-33. It caps RVs and trailers at 40 feet.
If you need more sleeping space or a longer rig than those loops allow, look at RV rentals across Idaho.
Teton Pass over the top dumps you in Jackson. That town and the Wyoming side of the range are Jackson campervan country.
Swan Valley and Palisades Reservoir
US-26 follows the Snake into Swan Valley. Palisades Reservoir opens against the Snake River Range, a wide sheet of water with the mountains on the far shore. The Rainey Creek ice cream stand is the landmark in Swan Valley.
Calamity Campground is the closest reservable overnight to Idaho Falls. The Forest Service takes reservations from late May through early September, and there are no hookups. Loop C does not take trailers. Use it as a first night out of town, or stay put if the water is the trip.
For the Sawtooths, the panhandle lakes, and the rest of the state, start from the Idaho campervan hub.