Lava Hot Springs to Island Park: Road Trip Guide

The route from Lava Hot Springs to Island Park follows US-91 north then US-20 west, covering about 120 miles. This drive crosses the Snake River Plain and ascends into the Yellowstone Plateau, offering dramatic geological transitions. In 1959, the nearby Hebgen Lake earthquake reshaped the landscape, a reminder of the region's volcanic activity.

Expect a driving time of roughly 2.5 hours without stops, but plan for a full day to savor the attractions. The route passes through small towns and vast national forests, with no major cities in between. This guide covers what to see, where to stop, and how to prepare for the journey.

US-91 north from Lava Hot Springs is a well-maintained two-lane highway, passing through farmland and small communities. At Idaho Falls, merge onto US-20 west, which becomes a four-lane divided highway for most of the way to Island Park. This section is relatively straight and fast, with occasional passing lanes.

Fuel is available in Lava Hot Springs, Idaho Falls, and Rigby, but the last stretch from Rigby to Island Park has sparse services. Plan to fill up before leaving Idaho Falls. Diesel and unleaded are widely available, but options for electric vehicle charging are limited.

Fuel and Route Economics

• The estimated fuel cost for a typical sedan is $15-20, based on current Idaho gas prices.
• There are no tolls on this route.
• Most rest areas and visitor centers are free to use.

For a more detailed look at planning stops and hidden gems, see how to find the best stops and hidden gems between cities.

US-20 is a high-speed road with sections of 65 mph, but watch for wildlife, especially deer and elk at dawn and dusk. Winter driving can be hazardous with snow and ice; check conditions before traveling. The road is well-maintained, but cell coverage is spotty between towns.

For families, several rest stops have playgrounds, and the Idaho Falls River Walk is stroller-friendly. Many restaurants and lodges are kid-oriented, and the hot springs are a hit with children (though some pools have age restrictions).

Pets are allowed in most outdoor areas but are restricted from some geothermal pools and certain trails. Always carry water and waste bags. For fatigue, plan stops every 1-2 hours; good options include the rest area near Heise and the Ashton Visitor Center.

Hidden off-route spots include the Heise Hot Springs, a local favorite just a few miles east of US-91, and the Teton Scenic Byway if you have time to detour. These are less crowded alternatives.

To manage fatigue, the drive can be broken at Idaho Falls, which has abundant amenities. The shoulder seasons (spring and fall) offer mild weather and fewer crowds, but winters are harsh. Culturally, the small towns along the route host local fairs and farmer's markets in summer.

The drive traverses the eastern edge of the Snake River Plain, a volcanic basalt region. As you approach Island Park, you enter the Caribou-Targhee National Forest, with dense lodgepole pine and meadows. The Henrys Fork of the Snake River runs parallel, offering fishing and rafting opportunities.

Notable natural attractions include the Lava Hot Springs themselves, a series of geothermal pools, and the Idaho Falls River Walk along the Snake River. Near Island Park, the Mesa Falls Scenic Byway provides views of Upper and Lower Mesa Falls, but note this adds 20 miles round trip.

Local commerce reflects the ranching and tourism economy. In Asia, look for independent cafés and gear shops. In Island Park, seasonal businesses cater to visitors heading to Yellowstone, but many close in winter. The area is part of the Greater Yellowstone Ecosystem, and while there are no UNESCO World Heritage Sites on the route itself, Yellowstone to the east is one.