West Yellowstone to Athol: Road Trip Guide

The drive from West Yellowstone, MT to Athol, ID follows US-20 West, a route that traces the path of the ancient Lake Missoula floods. These cataclysmic ice-age floods sculpted the channeled scablands you'll see near the Idaho border.

Learn how to find the best stops and hidden gems between cities to enrich your journey.

US-20 is a well-maintained two-lane highway for most of the journey, widening to four lanes near Idaho Falls. The route is mostly rural, with limited services between towns.

• Fuel stops: Available in West Yellowstone, Ashton, St. Anthony, and Rexburg.
• Cell coverage: Spotty between West Yellowstone and Ashton; reliable in larger towns.
• Road conditions: Clear in summer, but snow possible from October to May.

For a full fuel-cost estimate, use an online trip calculator. Plan to fill up in West Yellowstone, as gas prices are slightly higher in national park gateway towns.

Soon after leaving West Yellowstone, you'll cross the Continental Divide at Targhee Pass (elevation 7,073 ft). The landscape shifts from volcanic plateau to rolling farmland as you descend into the Snake River Plain.

Near Ashton, you can spot the Ashton Reservoir and the remains of ancient lava flows. In St. Anthony, the St. Anthony Sand Dunes offer a stark contrast—a 10,000-acre field of white gypsum sand.

Local commerce along the route centers on agriculture: potato farms, dairy operations, and grain elevators. In Rexburg, you'll find Walmart, fast-food chains, and local diners.

UNESCO World Heritage Sites are not directly on this route, but nearby Yellowstone National Park (a UNESCO site) begins just outside West Yellowstone.

The road is generally safe, but watch for wildlife (deer and elk) especially at dawn and dusk. In winter, carry chains; in summer, beware of sudden afternoon thunderstorms.

For family breaks, consider the following:

• Henry's Fork River picnic area near Ashton (restrooms, picnic tables).
• Rexburg Rapids Water Park in Rexburg (seasonal, kids' splash pad).
• Mesa Falls Scenic Byway detour (13 miles north of Ashton) for waterfalls.

Pet-friendly stops are limited; rest areas without facilities are common. The Idaho Falls rest area (just off the route) has pet-walking areas.

Plan to stop every 1-2 hours to avoid fatigue. The town of St. Anthony has a quiet park near the Teton River for stretching. For a unique hidden gem, drive a few miles south of Ashton to the Warm River Springs—a natural hot spring, but check local regulations before soaking.