Idaho Falls to Pullman: Road Trip Guide via US-20 & US-95

The 380-mile drive from Idaho Falls, ID to Pullman, WA along US-20 and US-95 crosses the Snake River Plain, skirts Craters of the Moon, and climbs into the rolling Palouse hills. This route bypasses interstate monotony for a genuine western journey. An estimated 6.5 hours of driving without stops rewards you with stark lava flows and wheat fields that shift from green to gold.

One specific fact: near Arco, Idaho, you'll pass the world's first nuclear power plant (EBR-I, now a museum). The road also traces the path of Lewis and Clark, whose Corps of Discovery crossed this region in 1805. For tips on unearthing lesser-known stops like the EBR-I or the Teton Flood Museum, see how to find the best stops and hidden gems between cities.

US-95 from Boise to Pullman has narrow shoulders, sharp curves, and occasional deer. Drive with caution at dusk and dawn. Winter can bring snow and ice, especially over White Bird Hill (elevation 4,000 ft). Summer thunderstorms produce sudden downpours. Rest areas are located at mile markers 26 (near Cambridge) and 108 (near Grangeville) on US-95, but they are basic (toilets, picnic tables).

For families, Craters of the Moon offers a Junior Ranger program and easy hikes like the 0.5-mile Devil's Orchard Trail. In Boise, the Discovery Center of Idaho has hands-on exhibits. Pet-friendly notes: most rest stops allow leashed pets; Craters of the Moon permits dogs on trails but not in buildings. Pullman's Kamiak Butte County Park has pet-friendly trails.

To combat driver fatigue, plan stops every 2 hours. Break suggestions: Arco (stretch legs, grab coffee), Mountain Home (rest area with vending machines), and Lewiston (riverside park). The hidden gems approach can help you find off-route spots like the Teton Flood Museum in Rexburg or the ghost town of Silver City near US-95.

The route primarily uses US-20 west to US-95 north. After Idaho Falls, US-20 runs arrow-straight across the desert to Arco, then gradually becomes more undulating near Mountain Home. US-95 from Boise to Pullman is a winding two-lane road through forested mountains and river canyons. Fuel stops are sparse between Arco and Mountain Home (about 130 miles), so fill up in Idaho Falls or Arco.

• Fuel cost estimate: $55-70 (regular gas at current prices, vehicle at 25 mpg).
• Best fuel stops: Idaho Falls (exit #118 on I-15), Arco (Sinclair station), Boise (multiple options), Lewiston (before final leg to Pullman).
• Restrooms: Available at Craters of the Moon Visitor Center, rest areas near Pine, Idaho, and in Boise.

Leaving Idaho Falls, the Snake River plain stretches west with distant mountain views. At Arco, the Big Lost River valley introduces sagebrush and volcanic buttes. Craters of the Moon National Monument just south of US-20 offers a surreal landscape of cinder cones and lava tubes—a must for geology buffs. North on US-95, the scenery shifts abruptly: the Payette River gorge, dense pine forests, and then the Palouse—a patchwork of rolling wheat farms that seem to glow in afternoon light.

Local commerce along the route includes small-town cafes in Arco (the Pickle's Place), fruit stands near Emmett (apples and peaches in season), and wineries around the Snake River Valley AVA. In Pullman, the downtown farmers market (Sundays May-October) showcases Palouse produce and crafts. For a unique souvenir, stop at the Idaho Potato Museum in Blackfoot (just off I-15, a short detour from Idaho Falls).