Idaho Falls to Moscow Road Trip Guide: Full Route Breakdown

Idaho Falls sits at 4,700 feet, Moscow at 2,600; the 340-mile drive on US-20 and US-95 drops 2,100 feet. The route crosses the Continental Divide at Monida Pass (6,923 ft) before descending into the Snake River Plain and the Palouse.

Expect 5.5–6 hours of driving, but stretch it to a full day. The road is mostly two-lane with some four-lane sections. This guide covers everything from fuel stops to hidden off-route spots.

Key highways: US-20 west from Idaho Falls to Arco, then US-93 north to Challis, and US-95 northwest through McCall to Moscow. The route bypasses Boise, offering a more direct path through central Idaho’s mountains and valleys.

For a general method to plan any road trip, see how to find the best stops and hidden gems between cities.

Start on the Snake River Plain with irrigated farmland. West of Arco, enter Craters of the Moon National Monument & Preserve – a sprawling lava field with cinder cones and caves. It’s a designated National Natural Landmark.

• Craters of the Moon: Drive the 7-mile loop, hike to Inferno Cone (views of the Great Rift).
• Lost River Valley: Home to Idaho’s tallest peak, Borah Peak (12,662 ft). Short, steep trail.
• Payette River Scenic Byway: US-95 from New Meadows to McCall follows the North Fork, with whitewater rafting and fishing spots.

UNESCO World Heritage Sites: None directly on route, but nearby are two: Yellowstone National Park (east of Idaho Falls) and the Salish-Spirit Cave (western Montana). Yellowstone is a 2-hour detour from Idaho Falls.

Local culture: In McCall, stop at the McCall Winter Carnival grounds (even in summer). Grangeville hosts the Border Days rodeo (July). Moscow is home to the University of Idaho, with a vibrant downtown and farmers market.

Fuel stations are sparse between Arco and Salmon (120 miles without services east of Challis). Fill up in Idaho Falls and again in Salmon. McCall and Grangeville have several stations.

• Gasoline cost: ~$3.50/gal (2025). Expect to fill twice (20–25 gallons total).
• Road quality: US-20 is good pavement; US-93 & US-95 vary with chip-seal and some gravel sections near construction zones.
• Cell coverage: Spotty in Lost River Valley and Payette National Forest; download offline maps.

Best time to drive: May–October for snow-free passes. Winter requires chains or 4WD on US-95 north of McCall and at Lolo Pass (but you aren't going there).

Major intersections: US-20/US-93 junction at Arco; US-93/US-95 junction at New Meadows.

Wildlife: Mule deer, elk, and cattle on open range. Dawn/dusk are peak collision hours. Bright headlights recommended. Some sections have no shoulders.

• Rest areas: Craters of the Moon visitor center (flush toilets, picnic tables), Salmon public restrooms (city park), McCall rest stop (US-95).
• Family stops: Idaho Falls’ Tautphaus Park Zoo (over 300 animals); McCall’s Ponderosa State Park (swimming, hiking); Moscow’s Appaloosa Museum.
• Pet-friendly: Many motels in Salmon, McCall, and Moscow accept pets (La Quinta, Super 8). Most national forest trails allow dogs on leash.

Fatigue management: The long, straight roads east of Arco can induce drowsiness. Stop every 2 hours. Good break points: Arco (mining museum), Challis (hot springs), McCall (lake walk).

Hidden off-route spots: Birch Creek Valley (off US-28 near Leadore) – scenic drive with fewer cars. Also, Stanley Lake (west of Sawtooth Valley) is a 30-min detour from Challis via ID-75.