East to West Coast Road Trip: Three Routes Across the Country Compared

East to West Coast Road Trip: Three Routes Across the Country Compared

The three best cross country routes east to west

Every full coast to coast line is well over 2,000 miles of interstate, so the drive itself takes several long days before you stop for anything. The national parks near each route are what make one better than another for you. This table puts them side by side.

Northern route: I-90 from Boston to Seattle

I-90 begins in Seattle and ends in Boston, passing through Chicago, southern Minnesota, South Dakota, Wyoming, Montana and the Idaho panhandle. It is the route for people who want the Great Plains and the northern Rockies, and it is the only one of the three that runs straight past the Yellowstone gateways.

• Badlands National Park. The park sits right off the interstate. Westbound, take Exit 131 at Interior and drive about three miles south to the Northeast Entrance. Eastbound, take Exit 110 at Wall and drive about seven miles to the Pinnacles Entrance. The Badlands Loop Road connects the two, so you can leave the interstate at one exit and rejoin it at the other.
• The Black Hills. I-90 skirts the north edge of Rapid City, the base for Mount Rushmore, Custer State Park and the Needles Highway. Our Badlands and Black Hills road trip covers three days here.
• Theodore Roosevelt National Park. Take the I-94 split instead of I-90 through the Dakotas and you pass Medora, the gateway to the park's South Unit. See the Theodore Roosevelt weekend itinerary.
• Yellowstone. Near Livingston, Montana, I-90 runs briefly with US-89, which heads south to Gardiner and the North Entrance. Our Chicago to Yellowstone guide covers the eastern half of this route and the Yellowstone 3 day itinerary covers the park itself.

The catch is weather. The mountain passes in Montana, Idaho and Washington see winter snow, and the plains get hard storms, so this route is best from late spring to early fall.

Central route: I-70 and I-80 across the middle

I-70 runs from near Baltimore through Columbus, Indianapolis, St. Louis, Kansas City and Denver, then ends at I-15 near Cove Fort, Utah. It does not reach the Pacific. From Cove Fort, I-15 south takes you past the Zion turnoff to Las Vegas and on toward Los Angeles. If you want to finish in San Francisco, I-80 is the coast to coast option: it runs from Teaneck, New Jersey through Toledo, Des Moines, Omaha, Cheyenne, Salt Lake City and Reno.

This is the route with the most national parks within a short detour of the interstate.

• Cuyahoga Valley. Reachable from I-80 and the Ohio Turnpike, and about 22 miles from Cleveland.
• Rocky Mountain. Leave I-70 at Denver for Estes Park. Timed entry reservations still run in 2026, through mid-October, so book before you arrive. Our Rocky Mountain 3 day itinerary has the details.
• Arches and Canyonlands. From I-70 at Crescent Junction, US-191 runs 22 miles south to the Arches entrance, just north of Moab, the base for both parks.
• Capitol Reef. From I-70 exit 149, Utah Highway 24 runs about 81 miles to the visitor center. The park warns not to trust GPS here, so carry a map.

Two of our trips are built around this stretch: the Colorado to Utah road trip from Denver to Moab, and the 7 day Utah national park road trip through Arches, Canyonlands, Capitol Reef, Bryce and Zion. Between them they turn the western third of this route into a trip of its own.

Plan around elevation. The Eisenhower Tunnel on I-70 west of Denver sits at 11,158 feet, the highest point on the Interstate system, and I-80 tops out at 8,640 feet at Sherman Summit in Wyoming. Both can see snow well outside winter. On I-80 in western Utah there are 37.4 miles between the Wendover and Knolls exits, so fill up before you leave either end.

Southern route: I-40 from North Carolina to California

I-40 runs from Wilmington, North Carolina to Barstow, California, through Knoxville, Nashville, Memphis, Oklahoma City, Albuquerque and Flagstaff. West of Oklahoma it follows the line of old Route 66. From Barstow, I-15 continues to Los Angeles.

• Great Smoky Mountains. Take Exit 407 at Sevierville and follow US-441 through Pigeon Forge into the park, or Exit 27 toward Maggie Valley and Cherokee on the North Carolina side. Our Great Smoky Mountains 3 day itinerary starts here.
• Petrified Forest. Like Badlands, a park you can drive straight through and rejoin the interstate on the other side. Westbound, leave I-40 at Exit 311, drive the 28 mile park road south to US-180, and follow US-180 about 19 miles to Holbrook, where you rejoin I-40 at Exit 285.
• Grand Canyon South Rim. About 60 minutes from I-40 at Williams, or 90 minutes from Flagstaff. See our South Rim 3 day itinerary.

This is the usual choice between November and March, since it avoids the high passes of the other two. It is not snow-free: the northern Arizona plateau around Flagstaff and Williams still gets winter storms. In summer, the desert stretch toward Barstow is the hot part.

How to choose

• You want Yellowstone or the Badlands: I-90.
• You want Utah's red rock parks: I-70, then I-15 or I-80.
• You are driving between November and March: I-40.
• You want to end in Seattle: I-90. In San Francisco: I-80. In Los Angeles: I-40 or I-70 with I-15.

If you have the time, do not come back the same way. Drive west on one route and east on another and you see twice as many parks for the same number of driving days. Once you reach the Pacific, the 14 day West Coast road trip runs the coast between Seattle and Los Angeles. For paper and app planning tools, see our national parks road trip map guide.