Jackson to Spearfish: A Wyoming-to-South Dakota Road Trip Guide

The route from Jackson, Wyoming to Spearfish, South Dakota runs 449 miles along US-26, US-287, I-25, and I-90, crossing the Continental Divide twice. It passes through the Wind River Canyon, a narrow gorge carved by the Wind River that exposes nearly 3 billion years of geologic time. The drive typically takes 7–8 hours without stops, but most travelers stretch it to two days to absorb the transition from alpine peaks to prairie badlands.

This guide answers key questions: best stops Jackson, WY to Spearfish, SD, how long to drive Jackson, WY to Spearfish, SD, is it worth driving Jackson, WY to Spearfish, SD, and things to do between Jackson, WY and Spearfish, SD. For a deeper methodology on planning intercity trips, see how to find the best stops and hidden gems between cities.

Fuel stations are concentrated in towns like Riverton, Shoshoni, Casper, and Douglas. Between these, stretches of 60–80 miles have no services. In the Wind River Canyon (mile 30–55 from Jackson), cell service is absent for about 25 miles.

• Estimated fuel cost for a sedan at $3.50/gal, 25 mpg: $63 total.
• WY-789 from Riverton to Casper is a two-lane road with occasional passing lanes; average speed 55–65 mph.
• I-25 from Casper to I-90 is wide and well-maintained, but can be affected by crosswinds near exit 140.

Road quality on US-26 is good except between Dubois and Riverton where winter frost heaves cause uneven pavement. I-90 through the Black Hills has frequent curves and a 65 mph limit. It's worth driving Jackson, WY to Spearfish, SD for the variety of landscapes, but plan for a full day or an overnight stop.

The journey crosses three distinct ecoregions: the Rocky Mountains, the Wyoming Basin, and the Black Hills. Near Shoshoni, the landscape flattens into sagebrush steppe with buttes like the Poison Spider Creek area.

• Wind River Canyon: Scenic pullouts at mile 48 offer views of the canyon walls and bighorn sheep.
• Boysen State Park: A reservoir with camping and fishing, located 5 miles off US-26 near Shoshoni.
• In Casper, the National Historic Trails Interpretive Center provides context on the Oregon, Mormon, and Pony Express routes.

Local commerce includes art galleries in Buffalo (detour 40 miles north via I-25) and the Spearfish Cultural Center with exhibits on the 1890s gold rush. Things to do between Jackson, WY and Spearfish, SD include visiting the Wyoming Dinosaur Center in Thermopolis (off US-26) and the Vore Buffalo Jump near Sundance, WY.

Wildlife crossings (deer, elk, antelope) are common at dawn and dusk, especially on US-287 through the Red Desert. In winter, check WYDOT cameras for I-80 closures that may divert traffic. Cell service is patchy; download offline maps.

• Rest areas: Riverton rest area (mile 125), Casper rest area (mile 275), and the Spearfish Valley rest area (exit 14 on I-90).
• Family stops: Casper's Children's Museum and Spearfish's Community Caves (easy walking trail).
• Pet-friendly: Many motels in Riverton and Casper accept dogs for a fee, and Spearfish has a fenced dog park at the City Park.

For fatigue management, the driver should take a 15-minute break every 2 hours. The Wigwam Motel in Holbrook, AZ is famous, but in Wyoming, the Jackson Lake Lodge offers a good stop. Alternatively, plan lunch at the Cowboy Cafe in Dubois. It is worth driving Jackson, WY to Spearfish, SD for the diversity of scenery, but break up the monotony with short hikes like the Bridal Veil Falls in Spearfish Canyon.