Idaho Falls to Yakima: A Road Trip Through the Snake River Plain

The drive from Idaho Falls, ID to Yakima, WA spans 540 miles along US-20 and I-84, roughly 8.5 hours without stops. This route follows the historic Oregon Trail, passing the geological marvel of Craters of the Moon. The Snake River Aquifer, one of the largest in the US, lies beneath much of this terrain.

Expect high desert plains, volcanic landscapes, and fertile valleys. The journey crosses the Continental Divide at an elevation of 7,088 feet near Monida Pass.

The primary route is US-20 from Idaho Falls to Boise, then I-84 west to Pendleton, OR, and finally US-395 north to Yakima. Fuel stations are abundant every 30-50 miles, but fill up before crossing the Blue Mountains. Gas prices are slightly lower in Twin Falls and Boise.

• Tolls: None on this route.
• Road surface: Generally good, but watch for frost heaves in early spring near the Oregon border.
• Weather alerts: Check conditions for the Blue Mountain passes in winter.

Learn more about how to find the best stops and hidden gems between cities.

I-84 is well-maintained, but sections near Boise can be congested during rush hour. In winter, carry chains for the Blue Mountain passes (elevation 4,500 ft). Cell reception is spotty between Arco and Mountain Home.

• Family-friendly stops: The Discovery Center in Twin Falls, Zoo Boise, and the Children's Museum in Pendleton.
• Pet-friendly: Many rest areas have leash-free zones; the Craters of the Moon allows pets on a leash.
• Fatigue management: Rest areas exist every 50 miles, notably the Oregon Trail Rest Area near Caldwell and the Blue Mountain Rest Area.

Hidden off-route spots: The ghost town of Silver City (45 min south of Boise) and the hot springs at Miracle Hot Springs (near Buhl). For local culture, stop at the Basque Museum in Boise or attend the Pendleton Whisky Music Festival in summer.

Craters of the Moon National Monument is a must-stop near Arco, ID. This volcanic field features lava tubes and cinder cones. Shoshone Falls in Twin Falls is the 'Niagara of the West,' plunging 212 feet. Further west, the Snake River Canyon near Boise offers scenic viewpoints.

• UNESCO World Heritage Sites: None directly on route, but nearby Yellowstone National Park is a World Heritage Site (180 miles north of Idaho Falls).
• Local commerce: Visit the Nampa Farmers Market (summer) or Pendleton's historic downtown with woolen mills and vintage stores.
• Best stops Idaho Falls, ID to Yakima, WA: Craters of the Moon, Shoshone Falls, Boise's Basque Block, Pendleton Underground.

Climatic conditions vary: High desert with hot summers (90°F+) and cold winters (below freezing). Spring and fall offer mild temperatures and colorful foliage. Route aesthetics peak in the Blue Mountains, where ponderosa pines frame the highway.