Bozeman to Thermopolis: A Scenic Drive Through Montana and Wyoming

The drive from Bozeman, Montana to Thermopolis, Wyoming covers roughly 300 miles along US-191 and US-20, tracing the western edge of the Gallatin National Forest and dipping into the high plains. This route, known locally as the 'Hot Springs Highway,' passes through the town of West Yellowstone—the busiest entrance to Yellowstone National Park—and follows the Wind River Canyon, a geological corridor that exposes 2.9 billion years of Earth's history.

Fuel stops are sparse between West Yellowstone and Dubois, so fill up in Bozeman or West Yellowstone. In West Yellowstone, the Conoco station offers premium fuel at ~$4.50/gal. Between West Yellowstone and Dubois, the only fuel is in Ashton, Idaho (Chevron) and Lake, Wyoming (gas station near Jackson Lake), but Lake is a 20-mile detour. Dubois has two gas stations with regular unleaded around $4.20/gal. Thermopolis has multiple stations; the Exxon on US-20 is convenient.

• Bozeman to West Yellowstone: 88 miles, no fuel between.
• West Yellowstone to Ashton: 45 miles, fuel in Ashton.
• Ashton to Dubois: 60 miles, no fuel until Dubois.
• Dubois to Thermopolis: 110 miles, no fuel for 80 miles until Shoshoni.

Estimated total fuel cost for an average sedan (25 mpg) is $50-$60. The route is well-maintained, but winter conditions can close US-191 over the Gallatin Range—check weather and chain laws. All roads are paved. Consider bringing extra water and snacks, as services are minimal in the middle leg.

The landscape transitions from the lush Gallatin Valley near Bozeman to the pine forests and volcanic terrain around West Yellowstone. South of West Yellowstone, US-20 runs through the Island Park caldera, part of the Greater Yellowstone Ecosystem—watch for bison and elk. Near Ashton, you'll see potato fields irrigated by the Henrys Fork.

Dubois sits at the foot of the Absaroka Range. The town is a hub for dude ranches and the National Bighorn Sheep Center. Stop at the Red Rock Antiques for local crafts. A few miles north of Dubois, the Wind River Canyon is a must-see: a dramatic narrows with exposed rock formations older than the Grand Canyon. Pull over at the Wind River Canyon Viewpoint (mile marker 14 on US-26).

Thermopolis is home to Hot Springs State Park, where you can soak in the world's largest mineral hot spring for free. The park has a bison herd and terraces similar to Mammoth. Local commerce revolves around the hot springs and tourism; visit the Wyoming Dinosaur Center with real fossils.

US-191 from Bozeman to West Yellowstone is a two-lane highway with limited passing zones; drive defensively, especially near the Gallatin River where fly fishermen park on shoulders. US-20 through Idaho is straight but can be windy. Between Dubois and Thermopolis, US-26 winds through Wind River Canyon with tunnels and sharp curves—obey speed limits (45 mph). Wildlife crossings are common: bison, deer, and bighorn sheep.

• Rest stops: West Yellowstone (visitor center, restrooms), Ashton (city park), Dubois (Ranger Station with facilities), and Shoshoni (gas station with picnic area).
• Child-friendly stops: Yellowstone's Grizzly & Wolf Discovery Center in West Yellowstone, Dubois' Bighorn Sheep Center, and Thermopolis' Hot Springs State Park (large soaking pools with lifeguards).
• Pet-friendly framework: Most roadside rest areas allow pets on leash. West Yellowstone's shops often have water bowls outside. In Thermopolis, the hot springs are not pet-friendly, but there is a pet daycare kennel at 307-864-2188.

Fatigue management: The drive can be monotonous after Ashton. Schedule breaks every 90 minutes. Stop at Mesa Falls Scenic Byway detour (12 miles east of Ashton) for a short walk to Lower Mesa Falls. If you need a longer rest, the town of Dubois has a quiet city park with shade. For those planning stops, here's how to find the best stops and hidden gems between cities.