Cody to Bonners Ferry Road Trip Guide: Wyoming to Idaho

The highway US-20 West from Cody, WY to Bonners Ferry, ID covers approximately 650 miles (1,050 km) and takes about 11–12 hours of pure driving time, but most travelers stretch it over three days to absorb the landscape. A specific nuance of this route: near Livingston, MT, the road crosses the 45th parallel, exactly halfway between the equator and the North Pole, a geographic marker often missed at 45°34′N.

This corridor traverses three states, two national parks (Yellowstone and Glacier), and one UNESCO World Heritage Site (Yellowstone). The driving quirk: in Idaho, US-95 briefly runs concurrent with ID-1 for a quarter-mile near Bonners Ferry, a rare example of a federal highway sharing a state route number.

This drive links two ecological regions: the high plains of Wyoming and the Rocky Mountain forests of Montana and Idaho. Near Cody, the Shoshone River carves through red-hued cliffs, a prelude to the volcanic plateau of Yellowstone.

In West Yellowstone, the Grizzly and Wolf Discovery Center offers captive wildlife viewing. For hidden off-route spots, detour to the Earthquake Lake visitor center (48 miles west of West Yellowstone), site of a 1959 quake that created a new lake and buried a campground.

• Natural attractions: Mammoth Hot Springs, Lamar Valley (wolf watching), Paint Pots.
• Commerce: handmade crafts at the West Yellowstone Visitor Center, huckleberry products in Bonners Ferry.

The most dangerous segment is US-191 between West Yellowstone and Bozeman, where winding roads and wildlife crossings cause frequent accidents. Drive at 55 mph max after dark. For fatigue management, stop at the Ennis Lake overlook (mile 45) to stretch legs and view the Madison Range.

Family-friendly stops: the Grizzly & Wolf Discovery Center (hands-on exhibits) and the Big Hole National Battlefield (interpretive trails). Pets are allowed in Yellowstone on boardwalks; leash laws strictly enforced. In Bonners Ferry, the Kootenai River Trail is a pet-friendly walk.

• Rest zones: pullouts near Hebgen Lake, rest area at mile 120 on US-287.
• Emergency services: limited between West Yellowstone and Ennis; keep a first aid kit.

Fuel stations are abundant in towns but sparse in the 100-mile stretch between West Yellowstone and Missoula. Plan to fill up in West Yellowstone or Ennis. Gas prices average $0.10–$0.20/gallon more in tourist areas; cheaper fuel is found in Missoula or Coeur d'Alene.

• Road quality: US-20 and US-287 are well-maintained two-lane highways; US-95 in Idaho is a divided highway but narrow in places.
• Cellular coverage: AT&T and Verizon have gaps in Yellowstone and Lolo National Forest; download offline maps.
• Weather: Summer highs 80°F, winter snow possible until May; always carry chains.