Sun Valley to Pocatello Road Trip Guide: Scenic Idaho Drive

The route from Sun Valley to Pocatello crosses the Arco Hills, where the Big Lost River vanishes into the Snake River Plain aquifer. This 140-mile drive (about 2.5 hours on US-20 and US-93) is a journey through volcanic landscapes and pioneer history.

Notably, the stretch southeast of Carey passes the Craters of the Moon National Monument, a vast field of lava flows and cinder cones. This road trip is worth the drive for its stark beauty and sparse traffic, offering a quiet alternative to I-84.

• Highways: US-20 east from Sun Valley, then US-93 south near Arco to Pocatello.
• Estimated driving time: 2 hours 30 minutes without stops.
• Key milestone: Mile marker 128 on US-20 marks the entrance to Craters of the Moon.

The road quality is excellent on US-20 and US-93, but watch for deer and cattle crossings, especially at dawn and dusk. Rest stops are available at the Craters of the Moon visitor center (picnic tables, restrooms) and in Arco.

• Family suitability: Craters of the Moon offers a family-friendly loop trail with caves and lava tubes.
• Pet-friendly: Allowed on leash at Craters of the Moon; service animals only inside buildings.
• Fatigue management: Divide the drive with a 20-minute stop at the Arco lava flow overlook (mile 110).

Hidden off-route spot: The Mormon Rocks near Darlington (south of Arco) are a colorful sandstone formation accessible via dirt road.

This route is well-maintained but remote. Fuel stations are sparse between Carey and Arco, so plan accordingly. Expect gas prices similar to national averages, with slight increases in tourist hubs.

• Best fuel stop: Arco has several stations; fill up before leaving Sun Valley.
• Economy: Using cruise control at 65 mph optimizes fuel economy on flat stretches.
• Hidden tip: The gas station in Carey often has cheaper fuel than Sun Valley.

Cell service is intermittent; download offline maps before departure. Emergency services are limited, so carry a spare tire and extra water.

The drive unfolds from the sagebrush steppe of the Wood River Valley to the lava fields of the Snake River Plain. Craters of the Moon is the centerpiece—a UNESCO World Heritage Site candidate (part of the National Park System).

• Key viewpoint: The Big Lost River sinks at the Great Rift, visible from US-20 near mile 130.
• Local commerce: In Arco, visit the Pickle’s Place for Idaho potatoes and homemade pies.
• Historic site: Atomic City (off US-26) is a defunct mining town with a gas station and a few buildings.

For more on finding hidden gems between cities, check out how to find the best stops and hidden gems between cities.