Paradise Valley follows the Yellowstone River on US-89 into Gardiner at the north gate. The Roosevelt Arch frames that entrance, and just inside it you get the travertine terraces at Mammoth Hot Springs. The Gardiner-through-Mammoth road is the only Yellowstone road that stays open to regular cars all year, and every other park road closes to cars from mid-December through mid-March.
Mammoth Campground is the year-round campground at that gate, the overnight next to those terraces. Length limits are 30 feet from mid-October through April and 45 feet from May through mid-October, as of September 2026. If you need more sleeping room than the winter cap allows, look at Montana RV rentals, and still match the pad. Yellowstone campgrounds book on two systems as of September 2026, Park Service sites including Mammoth on Recreation.gov and the concessioner campgrounds through Yellowstone National Park Lodges.
For a night in the valley before the gate, Pine Creek Campground is south of Livingston off US-89, reservable from mid-May through late September. Mallard's Rest on the Yellowstone River takes trailers up to 30 feet and stays open all year, which is the valley night when Pine Creek is shut. Chico Hot Springs in Pray is a day-use soak with no RV or van camping on the property.
The geyser basins are deeper in the park than this entrance. They are covered on the Yellowstone National Park campervan page.
Hyalite Canyon
South of Bozeman, Hyalite Canyon Road is the paved forest road up to Hyalite Reservoir. Langohr is the lower campground on that pavement, 12 miles from town. Hood Creek and Chisholm are the shoreline campgrounds at the water, on gravel spurs, and Hood Creek has a boat ramp on the reservoir.
Use this as night one when you are not already driving the valley toward Gardiner. The canyon road is open from mid-May through late March, so Langohr and the reservoir campgrounds are out of reach in spring mud. Back in town on MSU Bobcat football weekends, RV tailgating runs from Friday evening to Sunday noon, with a 36-foot limit.
Missouri Headwaters and Lewis and Clark Caverns
West on I-90 at Three Forks, the Jefferson, Madison, and Gallatin join and the Missouri starts, the confluence Lewis and Clark and Sacajawea moved through. Missouri Headwaters State Park is that meeting of rivers, with RV camping and no hookups, and reservations for some sites opening in mid-May.
Lewis and Clark Caverns State Park is the other Three Forks overnight, with RV hookups at the campground and a cave you only see on a guided walk. You walk lit limestone formations with a guide, stairs included. The Classic Cave Tour runs 2 hours and 2 miles, and cave access is guided only from May through September.
West Yellowstone and the Gallatin Canyon are on the Big Sky campervan page. The Beartooth Highway is the Billings campervan drive to Yellowstone's northeast entrance.