Spearfish to Kemmerer Road Trip: Scenic Byways & Fossil Riches

Spearfish, SD, and Kemmerer, WY, lie roughly 350 miles apart via Interstate 90 and US-14/16/20, a drive that typically takes 5.5 to 6 hours without extended stops. This route transitions from the pine-clad Black Hills through the high plains of Wyoming, ending in the high desert near the Utah border at an elevation of 6,956 feet.

Road quality is generally excellent, but watch for open-range cattle on US-20 near Worland—mind the signs. For rest, the Wyoming DOT maintains rest areas at key points; use them for stretching and fatigue management. Family-friendly stops include Devils Tower National Monument (visitor center, trails) and the Bighorn Canyon National Recreation Area near Lovell, with boating and fishing. For kids, the Wyoming Dinosaur Center features hands-on exhibits and guided quarry tours.

Pet-friendly framework: most hotels along the route accept pets, and many rest areas have designated pet-walking areas. Keep pets leashed near wildlife; bighorn sheep and pronghorn are common sightings.

Culinary infrastructure ranges from classic diners in Buffalo to taco trucks in Greybull. Try the bison burger at a local café, or pack a picnic from grocery stores in larger towns—is it worth driving Spearfish, SD to Kemmerer, WY? Absolutely, for the scenery alone, but the food adds to the experience.

Hidden off-route spots: the Medicine Lodge State Archeological Site (55 miles south of Buffalo) has ancient rock art, and the Fossil Butte National Monument (15 miles west of Kemmerer) preserves a 50-million-year-old lake bed with fish and palm fossils—an off-route detour worth the time. Things to do between Spearfish, SD and Kemmerer, WY include these prehistoric treasures.

For fatigue management, alternate drivers and plan stops every two hours. The route's long straight stretches on I-90 can induce drowsiness; pull over for a walk at the Powder River Pass viewpoint.

The route offers efficient fuel dynamics: gas stations cluster around Buffalo, Worland, and Greybull, with stretches between towns up to 70 miles—plan to fill up before leaving. Interstate 90 and US-16/20 are well-maintained, but winter weather can close mountain passes; check conditions for Powder River Pass (elevation 9,666 ft) on US-16.

• Driving time: 5.5 hours without stops (how long to drive Spearfish, SD to Kemmerer, WY).
• Best stops Spearfish, SD to Kemmerer, WY: Devils Tower, Bighorn Canyon, Fossil Butte.
• Speed limits: 80 mph on I-90, 70 mph on rural two-lane highways.

This route offers dramatic geological variety: the Black Hills' granite spires give way to the Bighorn Mountains' granite peaks, then the Absaroka Volcanic Province's basalt cliffs near Greybull. The Bighorn Basin is a hotbed of dinosaur fossils; the Wyoming Dinosaur Center in Thermopolis (about 40 miles off-route) houses a working quarry.

For UNESCO World Heritage Sites, the route passes near one: Yellowstone National Park, a 50-mile detour from Cody, WY. But closer to the main road, Devils Tower (a National Monument, not UNESCO) is a 50-mile side trip from I-90 near Sundance, WY.

Climate shapes the journey: expect cold winters with snow from November to March, and warm, dry summers perfect for hiking. The arid high desert near Kemmerer receives less than 10 inches of annual precipitation.

Local commerce thrives on ranching and energy extraction; you'll find cowboy bars in Buffalo and coal-mining heritage in Kemmerer. Learn how to find the best stops and hidden gems between cities to uncover offbeat spots like the Worland Dinosaur Quarry.