Green River to Spearfish Road Trip: Scenic Byways & Wild West

The drive from Green River, WY to Spearfish, SD spans 380 miles via US-191 and I-90, crossing the Continental Divide at an elevation of 7,075 feet. This route passes through the Red Desert, Wind River Canyon, and the northern edge of the Black Hills, offering a microcosm of Western landscapes.

Historic 1916: The Lincoln Highway, one of America's first transcontinental highways, roughly parallels parts of this route, with original segments visible near Green River and in Wyoming. Plan for at least 6 hours of driving time, but budget a full day to savor the scenery and attractions along the way.

Fuel stops are plentiful but spaced: every 60-80 miles in Wyoming, less frequent in South Dakota. Gas prices tend to be 5-10% cheaper in Wyoming due to lower state taxes. The route includes one toll-free section of I-90.

• Primary highways: US-191, US-20, US-16, I-90, and US-14.
• Highest pass: Powder River Pass on US-16 at 9,666 feet.
• Cellular coverage: Sparse across the Red Desert; more reliable near towns.

Wind River Canyon on US-20 between Shoshoni and Thermopolis offers a dramatic drive through 2,000-foot walls and is a designated Wyoming Scenic Byway. The canyon showcases a geological fault that exposes varied rock strata.

Road quality is generally excellent on I-90, but watch for wildlife (deer and antelope) at dawn and dusk. The route includes long stretches of two-lane highway where passing requires caution. Wyoming also has relatively low speed limits during winter storms.

• Weather: Summers are warm (80s°F), winters are cold and snowy (often below freezing).
• Best travel: May-September.
• Rest areas: Every 50-100 miles; include picnic tables and restrooms.

For families, the Wyoming Dinosaur Center in Thermopolis and the Wonderland Amusement Park in Spearfish are engaging stops. Pets are generally welcome at rest areas and campgrounds, but keep them leashed. Many motels along the route accept pets with a fee.

To manage fatigue, plan stops every 2 hours or 100 miles. The towns of Riverton, Buffalo, and Gillette offer ample services. For hidden gems, consider the Canyon of the Ancients or the Vore Buffalo Jump, a prehistoric buffalo jump site.

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

The Flaming Gorge National Recreation Area, 30 miles south of Green River, features red-hued cliffs and the Green River. It is a prime spot for fishing and boating. The route also skirts the northern edge of the Bighorn Mountains, where the Medicine Wheel National Historic Landmark—a 700-year-old Native American stone circle—sits at 9,642 feet.

The only UNESCO World Heritage Site near this corridor is Yellowstone National Park, located 200 miles northwest; the route itself does not hit any UNESCO sites directly. However, the Custer Battlefield (Little Bighorn) and Devils Tower are both within a short detour.

Local commerce along the way includes small towns like Buffalo, WY, where the historic Occidental Hotel (founded 1880) still operates and once hosted Buffalo Bill and Teddy Roosevelt. For a quick bite, try a local diner in Thermopolis or a bison burger in Ucross.

The route passes through rich Western history: the Oregon and Mormon trails crossed near Green River. In Spearfish, the Spearfish Canyon Scenic Byway (US-14) is a leafy contrast to the open plains.