Spokane to Green River Road Trip Guide: Scenic Drive

Driving from Spokane, WA to Green River, WY covers roughly 520 miles via I-90 and US-191, a route that traces the southern edge of the Rocky Mountains. One little-known fact: this stretch of I-90 passes through the historic Mullan Road, a 19th-century wagon route built by John Mullan that connected Fort Walla Walla to Fort Benton. Today, the journey takes approximately 8-9 hours of pure driving, but the diverse landscapes and unique stops make it worth much longer.

This guide answers the questions: is it worth driving Spokane, WA to Green River, WY? Absolutely—for the geology, history, and surprising culinary finds. For tips on uncovering hidden gems, check out how to find the best stops and hidden gems between cities.

The primary route is I-90 east from Spokane to Butte, MT, then south on I-15 to Idaho Falls, ID, and finally southeast on US-191 to Green River, WY. Road conditions vary dramatically: Washington and Montana sections are well-maintained, while Wyoming portions (especially US-191 between Rock Springs and Green River) may have rough patches.

• Worst traffic hours: Avoid Spokane I-90 between 7:30-9 AM and 4:30-6 PM. Montana sections are wide open except near construction zones.
• Toll roads: None on this entire route.
• Gas stations: Frequent in Washington and Montana (every 20-30 miles), but sparse in southern Idaho and Wyoming (every 40-50 miles). Always fill up in Butte or Idaho Falls.

From Spokane's pine forests to Wyoming's high desert, the landscapes shift dramatically. West of Butte, the Rocky Mountains dominate, with peaks over 10,000 feet visible from I-90. In Idaho, the Snake River Plain offers flat volcanic terrain, while US-191 snakes through the Bridger-Teton National Forest, home to elk and moose.

• Best scenic overlook: Homestake Pass (mile marker 208 on I-90) east of Butte, overlooking the Deer Lodge Valley.
• Local commerce stops: Butte's historic Uptown district has antique shops and the World Museum of Mining. Idaho Falls' farmer's market (Saturdays May-October) sells local huckleberry jam.
• Unique detour: Take US-20 from Idaho Falls to visit the sand dunes at St. Anthony (30 mins south).

Wyoming sections have strong crosswinds; reduce speed near Rock Springs. For families, the Idaho Falls Zoo at Tautphaus Park (open daily 10 AM-5 PM) is a great break. Pets are welcome at rest stops but must be leashed; the Butte Rest Area (eastbound I-90) has a designated pet area.

• Safety stretch: US-191 from Jackson to Green River is winding; watch for wildlife at dawn/dusk.
• Rest zones: Pull off at the Lost Creek Rest Area (mile marker 109 on I-90) near Bozeman—quiet with picnic tables.
• Fatigue tip: Drive 90 mins max between stops. Breakfast at Parked Goat Coffee in Butte is perfectly timed at 3 hours from Spokane.