Hill City to Kemmerer: A Geologic Road Trip Guide

US-16 west out of Hill City descends through the Pahasapa limestone that caps the Black Hills, the same formation that stores the region's groundwater. Over 500 miles later, you'll arrive in Kemmerer, Wyoming, where the Green River Formation holds one of the world's richest fossil fish deposits. The distance between these two landmarks—both geological treasures—makes for a road trip that's more than just a drive.

This guide covers the essentials: driving times, fuel strategies, natural attractions, and practical tips for families and pets. We've also included a table of key stats to help you plan. For more on discovering hidden gems along any route, see how to find the best stops and hidden gems between cities.

The route passes through the Black Hills National Forest, the Thunder Basin National Grassland, and the Red Desert of Wyoming. Each offers distinct scenery: granite peaks, rolling grasslands, and vast open spaces. Look for pronghorn antelope and wild horses in Wyoming's rangelands.

Near the midpoint, you can detour to the Oregon Trail Ruts and Register Cliff near Guernsey, Wyoming—pioneer-era carvings that are a local gem. In Kemmerer, don't miss the J.C. Penney Mother Store, the original 1902 dry goods store, now a museum.

Local commerce along the route is defined by small-town cafes and truck stops. In Buffalo, the historic Occidental Hotel serves meals in a setting straight out of the Old West. In Rawlins, try the local diners for a taste of Wyoming hospitality.

This section of Wyoming is also home to the Fossil Butte National Monument, a UNESCO World Heritage Site candidate (though not yet listed), which showcases the Green River Formation's incredible fossil fish. It's a must-see for any traveler interested in paleontology.

Driving this route in summer is generally safe, but be prepared for sudden afternoon thunderstorms and hail on the plains. In winter, heavy snow and ice are common—check weather forecasts and pack emergency supplies.

For families, the best stops Hill City, SD to Kemmerer, WY include the Museum of Geology in Rapid City, which has dinosaur exhibits, and the Wyoming Dinosaur Center in Thermopolis, a bit off route. For a quick break, let the kids run at the Buffalo Bill State Park near Cody (if you take the northern alternate).

Pet-friendly framework: Most rest areas allow pets on leashes, and many motels along I-80 accept dogs. Always carry water and a bowl for your furry companion.

Fatigue management is key on this long drive. Plan to stop every two hours. The town of Casper is a good halfway point with abundant lodging and restaurants. The rest area at South Pass City, the highest point on the route, offers a scenic but windy pit stop.

Hidden off-route spots include the Hot Springs State Park in Thermopolis (a short detour) and the Red Gulch/Alkali National Back Country Byway south of Shell, which offers solitude and geological wonders.

In terms of things to do between Hill City, SD and Kemmerer, WY, the list is endless: hiking in the Black Hills, visiting the Mammoth Site in Hot Springs (not to be confused with Hot Springs, AR), or exploring the Oregon Trail. Safe travels!

From Hill City, take US-16 west to Rapid City, then I-90 west to Buffalo, Wyoming. Continue on I-25 south to Casper, then I-80 west to Rawlins, and finally US-30/US-189 southwest to Kemmerer. The route is well-traveled and offers ample services.

• Fuel stops: Key towns for gas are Rapid City, Buffalo, Casper, Rawlins, and Rock Springs. Fuel prices in Wyoming are typically lower than in South Dakota.
• Road quality: I-90 and I-80 are well-maintained; US-30 is rural but in good condition. Watch for occasional potholes after winter.
• Rest areas: Official rest areas exist at mile markers, but many are seasonal. Plan for bathroom breaks at gas stations.

The drive from Hill City to Kemmerer is mostly interstate, but the scenery changes dramatically: from pine forests to high plains, then to the sagebrush steppe and finally the foothills of the Wyoming Range. The fastest route takes about 8 hours, but you'll want to factor in stops for meals and sightseeing.

If you're wondering is it worth driving Hill City, SD to Kemmerer, WY, the answer is a resounding yes, especially for geology enthusiasts and families. The journey offers a cross-section of the American West.