Idaho Falls to Red Lodge: Epic Road Trip Guide

The route from Idaho Falls, ID to Red Lodge, MT traverses the heart of the Greater Yellowstone Ecosystem, one of the largest intact temperate ecosystems on Earth. As you drive US-20 east and then US-191 north, you'll cross the Continental Divide at an elevation of 6,990 feet near West Yellowstone, and follow the Gallatin River through rugged canyons. This 330-mile journey takes approximately 6 hours without stops, but most travelers spend 8–10 hours exploring.

The highway passes through several distinct geological zones: the Snake River Plain volcanic basalt, the Madison Range limestone, and the Beartooth uplift granite. A local driving quirk: near the Montana-Idaho border, US-20 has a 55 mph speed limit through the Targhee National Forest, but wildlife crossing zones reduce it to 45 mph at night. Plan your fuel stops carefully, as the longest stretch without services is 65 miles between West Yellowstone and Big Sky, MT.

US-191 between West Yellowstone and Big Sky is a winding two-lane road with limited shoulders. Watch for wildlife—elk, bison, and bears are common at dawn and dusk. Speed cameras operate in West Yellowstone school zones (20 mph). For emergency services, dial 911; the nearest hospital is in Big Sky (70 miles from West Yellowstone).

Family and Child Suitability

• West Yellowstone's Yellowstone Historic Center has kid-friendly exhibits on firefighting and railroads.
• The Big Sky Tram (summer only) takes families to the 11,166-foot summit for panoramic views—a hit with older kids.
• Red Lodge's annual Festival of Nations (September) features parades and cultural booths.
• For a safe play break, the West Yellowstone playground at the Community Park has modern equipment.

Pet-Friendly Framework

Pets are welcome at many outdoor stops: the Gallatin River trail (leash required) and the Red Lodge city park. However, they are not allowed on Yellowstone boardwalks or inside park buildings. Pet-friendly motels include the Days Inn in West Yellowstone (pet fee $25) and the Rock Creek Resort in Red Lodge (no fee). Always carry a leash and water; summer temperatures can exceed 80°F.

Fatigue Management & Rest Zones

The route has limited rest areas. Plan breaks every 2 hours or 100 miles. Key rest zones: the Spencer Rest Area (mile 38 on US-20, vault toilets, no water), the West Yellowstone Visitor Center (flush toilets, picnic tables), and the Big Sky Rest Stop (seasonal, with interpretive signs). For longer breaks, stop at the Madison River Fishing Access (mile 12 on US-191) for a 15-minute walk by the river.

Hidden Off-Route Spots

Off the beaten path: the Earthquake Lake Visitor Center (mile 2 on US-287, 30-minute detour) commemorates the 1959 Hebgen Lake quake. The TeePee Creek Trailhead (mile 78 on US-212) offers a short hike to a waterfall. For a unique cultural stop, visit the Buffalo Bill Center of the West in Cody, WY (a 2-hour detour from Red Lodge via US-212). Insert this link: how to find the best stops and hidden gems between cities.

This route is a feast for geology enthusiasts. Leaving Idaho Falls, you cross the Snake River Plain, a vast volcanic plateau dotted with cinder cones and lava tubes. At US-20 mile marker 28, pull over at the Egin Bench overlook for a panoramic view of the Teton Range in the distance.

UNESCO World Heritage Sites

While the route itself isn't a UNESCO site, Yellowstone National Park (designated in 1978) is a must-visit detour. The park's west entrance is 10 minutes south of West Yellowstone. If time allows, a 2-hour loop to see Old Faithful covers 50 miles round trip.

Local Commerce and Culture

• In West Yellowstone, the Grizzly & Wolf Discovery Center offers a rehabilitation sanctuary (adults $14, children $9).
• Big Sky's Town Center hosts summer farmers' markets with local honey and huckleberry products.
• Red Lodge's historic downtown, listed on the National Register of Historic Places, features 19th-century saloons and the Carbon County Arts Guild.
• For culinary infrastructure, try the huckleberry pie at The Wildflower Bakery in Red Lodge, or the elk burger at The Corral in West Yellowstone.

Climate and Route Aesthetics

Best traveled May–October, when snow is absent. Summer temperatures range 70–85°F; July is the driest month. Fall brings golden aspens and fewer crowds. Winter requires 4WD and chains, but the snow-covered landscapes are stunning—especially the Gallatin Canyon with its frozen waterfalls. The best time for photography is early morning, when the light hits the granite cliffs along US-191.

The route primarily follows US-20 east from Idaho Falls to West Yellowstone, then US-191 north to US-89 at Gardiner, and finally MT-78 east to Red Lodge. The entire road is paved and maintained year-round, though winter conditions can be severe. For real-time road conditions, call 511 for Idaho and Montana.

Fuel and Route Economics

• Idaho Falls has the cheapest gas (averaging $3.20/gal as of 2025), while West Yellowstone charges a premium (up to $4.50/gal).
• Big Sky and Red Lodge have moderate prices ($3.80–$4.00/gal).
• Plan to fill up in Idaho Falls and again in West Yellowstone if needed; the 65-mile stretch between West Yellowstone and Big Sky has no gas stations.

Accommodation Options

• Idaho Falls: Budget motels ($80–$120/night) near Broadway Ave.
• West Yellowstone: Premium lodges ($200–$300/night) and campgrounds ($35–$50/night).
• Big Sky: Ski resort hotels ($250–$400/night) and vacation rentals.
• Red Lodge: Historic inns ($100–$180/night) and charming B&Bs.