Twin Falls ID to Dillon MT Road Trip Guide

The route from Twin Falls, Idaho to Dillon, Montana follows US-93 and I-15 for roughly 350 miles, crossing the Snake River Plain and ascending into the Beaverhead Mountains. This drive is notable for its dramatic shift from arid high desert to alpine conifer forests, passing within view of the Continental Divide at Monida Pass (6,860 ft). Along the way, you'll encounter the least-visited national monument in the lower 48 and ghost towns that harken back to the mining era.

The total driving time is approximately 5.5 hours without stops, but plan for a full day to explore. Fuel stations are sparse between Arco and Dillon, especially along US-93 through Idaho's Lost River Valley. Fill up in Twin Falls or Arco; the next reliable gas is in Lima, MT, about 160 miles later.

• Cell service: Reliable through Twin Falls to Arco; spotty between Arco and Dillon, especially in mountain passes.
• Road condition: US-93 is two-lane with occasional passing lanes; I-15 is well-maintained interstate. Watch for wildlife at dawn/dusk.
• Recommended stop: Arco – the first city in the world to be lit by nuclear power (1955).

From Twin Falls, the Snake River Canyon presents the Shoshone Falls (more than 200 ft taller than Niagara in spring). As you drive north, the landscape flattens into sagebrush steppe before rising toward the Lost River Range. Just west of US-93 lies Craters of the Moon National Monument: a vast lava field with cinder cones and caves. This UNESCO-nominated site (not a World Heritage site but on the tentative list) offers a 7-mile loop drive and hiking trails.

Approaching the Montana border, the highway climbs over Monida Pass, where the terrain transforms into lodgepole pine and aspen. Dillon, a ranching town at the foot of the Beaverheads, serves as a gateway to the Centennial Valley and Red Rock Lakes National Wildlife Refuge. For hidden gems, detour east on ID-22 to Million Dollar Springs (hot spring) near Arco, or ghost town Gilmore (off I-15 exit 23).

• Best stops: Craters of the Moon, Shoshone Falls (spring), Lima Dam viewpoint.
• Local commerce: Twin Falls has chain retailers and local cafes (Rock Creek); Dillon offers Western wear stores and the Patagonia outlet.

Long, straight sections of US-93 can induce highway hypnosis. How to find the best stops and hidden gems between cities includes advice on breaking up the drive every 2 hours. Recommended rest zones: the rest area near Arco (milepost 123) and the Montana Welcome Center at Monida Pass.

For families, Craters of the Moon is highly suitable — the visitor center has hands-on exhibits and cave exploration for kids. Pets are allowed on leashes on all trails and in the campground. In Dillon, the Beaverhead County Museum (fee) offers indoor restrooms. Pet-friendly lodging: Super 8 Dillon allows pets at no extra charge.

1. Fatigue management: Stop at Shoshone Falls or Craters of the Moon for a 30-min walk.
2. Fuel safety: Carry extra water and a blanket; winter driving (Nov-Mar) requires snow tires.
3. Hidden off-route spot: The Idaho National Laboratory’s Experimental Breeder Reactor I (EBR-I) near Arco – open for tours in summer.