Keystone SD to Pinedale WY: Epic Road Trip Guide

Leaving Keystone, South Dakota (elevation 5,200 ft) and heading west to Pinedale, Wyoming (elevation 7,175 ft) takes you on a 340-mile journey that climbs over 2,000 feet in elevation. Most of the drive follows I-90 west to I-25 north, then I-90 west again, but the real character emerges when you leave the interstate near Buffalo, Wyoming, and take US-16 west through the Big Horn Mountains.

This route crosses the Continental Divide twice and passes through three distinct geologic provinces: the Black Hills, the High Plains, and the Rocky Mountains. It's a drive that can be done in a single day (about 5 hours and 30 minutes of pure driving time), but savvy travelers budget at least two days to explore the natural wonders and historic towns along the way.

The Black Hills give way to the Great Plains just west of Newcastle, offering a sweeping transition from pine forest to shortgrass prairie. The first major landmark is Devils Tower National Monument (exit 154 on I-90), the first declared U.S. National Monument (1906) and site of the alien landing scene in Close Encounters of the Third Kind. A short detour to the visitor center offers views of the 867-foot volcanic plug.

Crossing into Wyoming, the Big Horn Mountains rise abruptly—a fault-block range that includes Cloud Peak Wilderness, where alpine lakes and wildflower meadows reward a short hike on the West Tensleep Trail. The dramatic descent down the west side leads to Ten Sleep Canyon, famous for its limestone cliffs and trout fishing.

Local commerce along the route is anchored in small towns like Newcastle, Buffalo, and Worland, where you can find family-run motels, diners serving chicken-fried steak, and gift shops selling Western memorabilia. In Thermopolis, don't miss the Hot Springs State Park—home to the world's largest mineral hot spring, free to the public.

UNESCO World Heritage Sites

While no UNESCO sites lie directly on this route, Yellowstone National Park (a UNESCO site since 1978) is only a two-hour drive from Pinedale via US-191 and US-26. Plan a detour if time allows.

For a taste of local culture, stop at the Buffalo Bill Center of the West in Cody (1 hour north of Pinedale) to see the finest collection of Western art and artifacts, including works by Frederic Remington and Charlie Russell.

To enrich your trip, learn how to find the best stops and hidden gems between cities and make your travel unique.

From Keystone, take US-16 south to Custer, then US-16 west to Newcastle. Jump onto I-90 west at Moorcroft, follow it to Buffalo, and then take US-16 west over the Big Horns. After Greybull, continue on US-16/US-20 west to Worland, then US-16 west again through Thermopolis and Dubois, finally reaching Pinedale via US-191 south.

Fuel economy varies widely by vehicle; a mid-size sedan averaging 30 mpg will need about 11 gallons for the 340-mile trip. At current national average gas prices ($3.50/gal as of early 2025), that’s roughly $38 in fuel. However, remote stretches in Wyoming often have higher prices (up to $4.20/gal), so fill up in larger towns like Buffalo or Worland.

Most of the route is well-paved, but the drive over the Big Horn Mountains (US-16) includes steep grades and sharp hairpin turns, requiring extra caution for RVs and trailers. Cell service is spotty in mountainous sections, so download offline maps before you go.

Key Logistics Facts

• Total distance: 340 miles
• Fastest route: Via I-90 and US-16 (5h30m)
• Scenic alternative: Add 2 hours via Badlands and Wind River Canyon
• Best fuel stop: Buffalo (last big town before the mountains)
• Road quality: Good, but watch for winter closures at Powder River Pass

The route is generally safe, but winter can bring icy conditions at higher passes, so check weather forecasts and carry chains. Speed limits are 75 mph on interstates and 65 mph on two-lane roads; patrol is active, so adhere strictly.

For families, the drive offers numerous educational stops: the Journey Museum in Rapid City (east of the start), the Wyoming Dinosaur Center in Thermopolis, and the National Museum of Wildlife Art in Jackson (south of Pinedale). Kids will love the free-flowing hot springs and the chance to spot bighorn sheep and deer in the mountains.

Pets are welcome at most roadside rest areas and campgrounds, but national park visitors must keep dogs on leashes at all times. Many motels in Buffalo and Pinedale are pet-friendly, but always call ahead to confirm.

Hidden Off-Route Spots

• Wind River Canyon (on US-20 between Shoshoni and Thermopolis) offers incredible geology and bighorn sheep.
• Sinks Canyon State Park near Lander has a phenomenon where the Popo Agie River disappears into a cave and reemerges a quarter-mile downstream.
• The historic town of Dubois preserves an Old West atmosphere with wooden boardwalks and a nightly bighorn sheep feeding program.

Fatigue Management & Rest Zones

Plan to stop every two hours. Reliable rest areas exist at Newcastle (eastbound), Buffalo (westbound), and Dubois. Consider an overnight stop in Buffalo or Thermopolis to break the drive into two relaxed segments and avoid driver fatigue.