Sun Valley to Custer: Epic Road Trip Guide

This 930-mile route from Sun Valley, ID to Custer, SD traces the edge of the Rocky Mountains. You'll cross the Continental Divide at Togwotee Pass (elevation 9,658 feet). It's one of the few drives where you can see a grizzly bear and a bison in the same day.

The journey follows US-20, US-26, and I-90. Most travelers complete it in two days, but three days allow for deeper exploration. For tips on finding unexpected treasures, see how to find the best stops and hidden gems between cities.

Infrastructure Safety & Road Quality: I-90 is excellent; US-26 is well-maintained but winding. Watch for wildlife at dawn/dusk: elk, deer, moose. Carry a spare tire; cell coverage is spotty in national forests.

Family and Child Suitability: Kid-friendly stops include the Jackson Hole Children's Museum, the National Bighorn Sheep Center in Dubois, and the Hot Springs State Park in Thermopolis (free soaking).

Pet-Friendly Framework: Most motels along I-90 accept pets. Grand Teton allows dogs on paved paths only. Carry water and waste bags; temperatures can be high on the plains.

Hidden Off-Route Spots: Detour to the Red Desert (south of US-20) for paintbrush-colored badlands. Or try the frozen-in-time ghost town of Kirwin (accessible via forest roads near Meeteetse).

Fatigue Management & Rest Zones: Rest areas are about every 50 miles on I-90. Planned stops: Idaho Falls (greenbelt walk), Jackson (lunch at the Snake River Brewery), Buffalo (overnight at the Occidental Hotel).

Culinary Infrastructure: Regional specialties: huckleberry shakes in Idaho, buffalo burgers in Wyoming, and chislic (fried meat cubes) in South Dakota. Notable eateries: The Bunnery in Jackson, The Cowfish in Buffalo, and the Alpine Inn in Hill City.

Key highways: US-20 East, US-26 East, I-90 East. The most scenic stretch is US-26 through Grand Teton National Park. Plan fuel stops in Idaho Falls, Jackson, Dubois, and Buffalo—rural sections can be 80 miles between stations.

Fuel and Route Economics: Gas prices vary; budget $120–$150 for a typical SUV. Road tolls: none. National park entrance fees: $35 for Grand Teton (valid 7 days). Speed limits: 65–75 mph on interstates, 55–65 on rural roads.

• Idaho Falls: Last major city for supplies before Jackson.
• Dubois: Small town; fill up before crossing Togwotee Pass.
• Buffalo: Good fuel and lodging options.

Climatic Conditions & Route Aesthetics: The best months are June–September. Togwotee Pass can have snow as late as May. Summer temperatures: 70–80°F in valleys, 50–60°F at high passes. Fall foliage peaks late September.

Natural Landscapes & Attractions: The route passes through Grand Teton National Park, Bridger-Teton National Forest, and the Bighorn Mountains. Key stops:

• Jackson Hole: A valley with jagged peaks and the Snake River.
• Togwotee Pass: Panoramic views of the Absaroka Range.
• Thermopolis: Home to the world's largest mineral hot spring.
• Bighorn National Forest: Dramatic canyons and alpine meadows.
• Devils Tower National Monument: Massive butte near the South Dakota border.

UNESCO World Heritage Sites: The route includes no UNESCO sites directly, but Yellowstone National Park (a World Heritage Site) is a short detour from West Yellowstone, MT (about 1 hour from the main route). The drive near Grand Teton is also a biosphere reserve.

Local Commerce & Culture: In Jackson, browse Western art galleries and cowboy-themed shops. Thermopolis offers the Wyoming Dinosaur Center. Buffalo has a historic downtown with craft breweries. Sundance, WY, is the former home of the Sundance Kid.