Sun Valley to Driggs: Guide to Idaho's Highway 75 & 20

The 140-mile drive from Sun Valley, ID to Driggs, ID along US-20 and ID-33 is a journey through Idaho's wild heartland. This route traverses the Big Lost River Valley, climbs over the Bitterroot Range at 7,000+ feet, and descends into the Teton Basin with views of the Grand Teton. The highway was originally a Native American trail linking the Salmon River and Snake River watersheds. Local lore says the 1860s Goodale’s Cutoff, an alternative to the Oregon Trail, crossed this exact corridor. Today, drivers should anticipate 2 hours and 30 minutes without stops, but the journey deserves at least 4 hours to explore scattered hot springs, historic ranches, and the Craters of the Moon National Monument's northern edge.

Route Overview

Start at the intersection of ID-75 and US-20 in Sun Valley. Head east on US-20 for 110 miles, then turn north onto ID-33 for the final 30 miles into Driggs. The entire paved two-lane highway is well-maintained, though sections near Craters of the Moon can be windswept. Fuel stations cluster in Sun Valley, Bellevue, Arco (mile 55), and Driggs. Between Arco and Rexburg (mile 105) is a 50-mile fuel desert.

Road Conditions

• From Sun Valley to Carey (mile 20): Hilly, frequent winds, watch for livestock.
• Carey to Arco: Flat high desert, rough shoulder in places.
• Arco to Mud Lake: Washboard surface, minor frost heaves.
• Mud Lake to Rexburg: Straight, smooth asphalt.
• Rexburg to Driggs: ID-33 climbs 1,500 ft over 30 miles, sharp curves near Tetonia.

Check how to find the best stops and hidden gems between cities for en route planning.

Natural Landscapes & Attractions

US-20 skirts the northern boundary of Craters of the Moon National Monument (mile 50). The lava fields, cinder cones, and sagebrush steppe create an otherworldly tableau. Further east, the Big Lost River Valley reveals irrigated potato fields alongside dry ranches. Near Rexburg, the Henrys Fork of the Snake River cuts a deep canyon. The final stretch into Driggs offers unobstructed Teton Range panoramas, with the Grand Teton dominating the southern skyline.

• Coal Geyser at mile 40 (unpredictable eruption, 2-3 feet tall).
• Little Lost River sinkhole (mile 45) where the river disappears into limestone.
• Mackay Reservoir (detour 15 miles north) for bird-watching.

Fuel and Route Economics

Gas prices vary: Sun Valley avg $3.80/gal, Arco $3.50, Driggs $4.00. The Sav-Mor in Arco is reliable. EV charging: Tesla Supercharger in Rexburg (mile 105), Level 2 at Driggs City Hall. The route cost approximately $35 for a sedan (30 mpg) at $3.60 average.

UNESCO World Heritage Sites

No UNESCO sites directly on route, but Yellowstone National Park (a UNESCO World Heritage Site) is 90 miles north of Rexburg via US-20. The Teton Range, part of Greater Yellowstone Ecosystem, is a tentative UNESCO site. The Craters of the Moon is a National Monument but not UNESCO-listed.

Climatic Conditions & Route Aesthetics

Summer: 80-95°F, clear skies, dust devils. Fall: 40-70°F, gold cottonwoods, elk bugling. Winter: -10 to 30°F, US-20 may ice, ID-33 requires chains. Spring: 30-60°F, occasional highway flooding near Mud Lake. Best viewing times are early morning or late afternoon for low-angle light on the Tetons.

Culinary Infrastructure

Arco: Pickle's Place (burgers, shakes) and Arco's Main Street Diner. Rexburg: Great Harvest Bread Co., and El Herradero Mexican. Driggs: Forage & Feast (seasonal American) and Teton House pizza. In between, pack a picnic from Sun Valley's Atkinsons' Market. No gourmet options between Carey and Rexburg.

Family and Child Suitability

This route suits families due to multiple short activity stops. The Kids Playground in Arco (mile 55) offers a shaded playset. Craters of the Moon has a Junior Ranger program. The Teton Valley Youth Center in Driggs has indoor play. Parents should plan for rest stops every 90 minutes to prevent restlessness.

Pet-Friendly Framework

Many outdoor stops are pet-friendly: Craters of the Moon allows dogs on trails (leashed) except in caves. The Arco rest stop has a small dog run. Driggs' Bistro 7 even provides water bowls. Beware of rattlesnakes near lava fields in summer—keep pets on trail.

Infrastructure Safety & Road Quality

Road quality is generally good. Watch for livestock on US-20 between Carey and Arco (open range). ID-33 at mile 125 has a 500-foot drop without guardrail. The speed limit drops to 35 mph through Rexburg. Cell service (ATT/Verizon) is unreliable between mile 30-100; download offline maps.

Hidden Off-Route Spots

Two miles south of Arco (turn at mile 54), the Experimental Breeder Reactor No. 1 offers free tours. 10 miles north of Arco via ID-93, the ghost town of Gilmore has 19th-century cabins. Near Rexburg, the Egin Lake sandy beach (mile 110) is a local swimming hole. In Driggs, the Grand Crag climb starts at the end of Ski Hill Road.

Fatigue Management & Rest Zones

Official rest stops at Carey (mile 20) and Arco (mile 55). The Arco rest area has bathrooms, vending machines, and picnic tables. Alternate stop: the Antelope Rest Stop at mile 80 has pit toilets and shade. The Driggs Visitor Center (at journey's end) provides information and clean restrooms.

Local Commerce & Culture

Arco's Main Street has antiques shops and the Craters of the Moon Coffee. Rexburg features BYU-Idaho's campus and the Rexburg Rapids water park. Driggs hosts weekly farmers' markets (summer) and the Teton Valley Brewery. Handmade leather goods at Drovers Mercantile in Driggs are a unique souvenir.