Missoula to Kemmerer: Drive Through Montana & Wyoming

This 430-mile route follows I-90 east from Missoula to Bozeman, then US-191 south through Yellowstone's western edge, and US-189 into Kemmerer. The drive takes 7–8 hours without stops, but the journey deserves days.

Near West Yellowstone, the highway crosses the Continental Divide at an elevation of 7,000 feet. This hydrological apex sends rainwater to the Pacific and Atlantic oceans. It's a geographic quirk few drivers notice.

For tips on finding hidden gems, see how to find the best stops and hidden gems between cities.

This route threads the Gallatin National Forest and skirts Grand Teton National Park. The landscapes shift from Montana's pine hills to Wyoming's sagebrush steppe.

• Yellowstone National Park: West entrance is 5 miles from West Yellowstone. Old Faithful is 30 miles south. Entry fee $35/vehicle.
• Grand Teton National Park: US-191 runs along the park's eastern boundary. Views of the Teton Range. Stop at Snake River Overlook.
• Local commerce: West Yellowstone has gear shops; Kemmerer has a historic downtown with the J.C. Penney birthplace.

Best stops: Earthquake Lake (Hebgen Lake), Quake Lake Visitor Center. In Kemmerer, visit Fossil Butte National Monument, a UNESCO fossil site.

Temperature ranges: July averages 80°F (27°C) in Bozeman, 70°F (21°C) in West Yellowstone. Winter can drop to -20°F.

Planning fuel, food, and rest stops along I-90 and US-191 keeps the trip smooth. Remote stretches require preparation.

• Fuel: Fill in Missoula, Butte, Bozeman, West Yellowstone. Last cheap gas before Kemmerer is in Jackson, WY.
• Road quality: I-90 is excellent; US-191 through Yellowstone has seasonal construction. Check road conditions.
• Rest stops: Ruby Creek Rest Area (I-90 exit 459), West Yellowstone Visitor Center. Kemmerer has basic services.

Cost breakdown: Missoula gas ~$3.50/gal, Kemmerer ~$3.60. Total fuel for 430 mi at 25 mpg: ~$60.

Safe driving requires attention to wildlife, weather, and distance between services. Families and pets need dedicated planning.

• Wildlife: Dawn/dusk on US-191; bison, elk, bears. Slow down near Yellowstone. No roadside feeding.
• Family stops: Butte's Berkeley Pit, Bozeman's Museum of the Rockies, West Yellowstone's Grizzly & Wolf Discovery Center.
• Pet-friendly: Most rest stops allow pets; national parks restrict pets on trails. Kennels available in West Yellowstone.

Fatigue management: Drive 2 hours then stop for 15 minutes. Use rest areas at mile markers 459 (Ruby Creek), 400 (Butte).

Hidden off-route spots: Big Sky (45 min drive from Bozeman), Virginia City (ghost town, 1 hr from Butte).