Lava Hot Springs

Lava Hot Springs is the crown jewel of Idaho’s geothermal recreation — a charming small town tucked in the canyon of the Portneuf River in southeastern Idaho, built entirely around the natural hot springs that well up at the town’s edge. The springs have been a gathering place for thousands of years, and the Lava Hot Springs Foundation today operates a world-class facility with natural mineral soaking pools and a large swimming and diving complex.

The hot springs flow at temperatures between 102 and 112 degrees Fahrenheit, naturally odorless and rich in minerals, filling a series of outdoor soaking pools that operate year-round. Alongside the soaking pools, the Olympic-sized swimming complex offers pools, water slides and diving boards. The Portneuf River flowing through town is a popular tubing and rafting stream in summer. A uniquely pleasant combination of geothermal soaking, swimming and small-town Idaho charm, Lava Hot Springs is a treasured natural and cultural icon of southeastern Idaho.

The two main Foundation facilities offer distinct experiences: the hot springs pools (natural geothermal mineral pools at varying temperatures up to 112 °F, open year-round) for soaking and relaxation, and the Olympic swimming complex (with Olympic-sized pools, a 50-meter pool, water slides and diving boards, open in summer). The Portneuf River through town is tubed and paddled in summer — local outfitters rent tubes and drop visitors upstream for a scenic float into town. The surrounding Caribou-Targhee National Forest offers hiking, and the Caribou Highlands above town provide mountain scenery. Soaking in the natural hot springs, swimming in the Olympic complex and tubing the Portneuf are the signature Lava Hot Springs experiences.

The hot springs pools are open and wonderful year-round — soaking in hot mineral water under a winter sky with snow on the surrounding hills is a classic Lava Hot Springs experience, and the pools are never too cold even in January. Summer adds the swimming complex, the water slides and the Portneuf River tubing. The town is busy year-round and especially packed on summer weekends and holidays; midweek visits are far more relaxed. Spring and fall offer mild weather with smaller crowds and full hot springs access. The hot springs are a genuine year-round draw — come in winter or the shoulder seasons for the best balance of experience and crowd.

The hot springs at Lava have been used for thousands of years — the Shoshone-Bannock and other Native peoples held the springs as a neutral gathering place, coming from great distances to soak and convene at the healing waters. The springs were encountered by Lewis and Clark-era explorers and became known to settlers and travelers. In 1902 the state of Idaho acquired and began developing the springs for public use, creating one of the first state recreational facilities. The Lava Hot Springs Foundation, a state agency, has operated the facilities ever since. Lava Hot Springs preserves this long-revered geothermal treasure and its tradition of public gathering, a cherished icon of southeastern Idaho.

The Lava Hot Springs geothermal system is fed by rainwater and snowmelt that percolates deep into the earth through faults and fractured rock of the Portneuf Valley, is heated by geothermal energy from the volcanic activity of the region (the broader eastern Snake River Plain volcanic system), and returns to the surface at temperatures of 102 to 112 °F. The water is naturally free of sulfur odor (unlike many hot springs) and naturally rich in minerals including sodium, potassium and carbonate. The deep circulation through heated rock, the faulted valley and the volcanic heat source created these warm, clear, mineral-rich springs.

The Portneuf River canyon and the surrounding mountains of the Caribou Range host mule deer, moose, elk, black bears, beavers along the river, and a rich birdlife of raptors, waterfowl and songbirds. The warm outflow from the springs creates a microhabitat of lush riparian vegetation along the river even in winter. The surrounding Caribou-Targhee National Forest supports robust wildlife populations. While the town and its facilities are the draw, the Portneuf River and the mountains above offer fine wildlife watching for those who venture beyond the pools.

The hot springs flow into the Portneuf River, a tributary of the Snake River, and the geothermally warmed outflow creates a distinct thermal plume in the cold river — a microhabitat of unusual character. The Portneuf Valley and surrounding Caribou Range support mixed forest, sagebrush and mountain meadow ecosystems with diverse wildlife. The springs themselves, with their constant warm outflow and mineral-rich water, support specialized algae and microorganisms. Protecting the springs’ catchment, the Portneuf River’s water quality and the surrounding forest sustains both the geothermal system and the ecology of the canyon.

Lava Hot Springs holds a beloved place in Idaho’s culture — the state’s most popular hot spring destination, a small canyon town where Idahoans and visitors have gathered to soak, swim and relax for well over a century. The springs were a neutral meeting place for Native peoples for thousands of years before Euro-American settlement, and that tradition of gathering and renewal continues today. The combination of natural mineral soaking, a great swimming complex and a charming small town on a beautiful river makes Lava Hot Springs unique among Idaho’s many geothermal features.

Lava Hot Springs is in southeastern Idaho, on U.S. Highway 30 in the Portneuf River canyon between the cities of Pocatello (30 minutes west) and Soda Springs, and about two and a half hours from Salt Lake City. The Foundation operates two facilities in town: the hot springs pools complex (east end of town) and the Olympic swimming complex (west end), both open to the public for a per-person fee. The town has motels, B&Bs and vacation rentals. The pools and swimming complex have separate admission fees and hours; check the Lava Hot Springs Foundation website for current fees, hours and any reservation requirements before visiting.

The Lava Hot Springs Foundation, a state agency, protects and manages the springs and facilities. Visitors help by following pool rules (shower before entering, no soaps or shampoos in the mineral pools, respect quiet in the soaking area), respecting the natural resource by not damaging the pools or geothermal infrastructure, and keeping the Portneuf River and its canyon clean. The geothermal system is a finite natural resource that requires careful management. Protecting the springs’ catchment, the Portneuf River and the town’s natural setting sustains the long tradition of gathering and renewal at this cherished Idaho spring.

The hot springs pools reach up to 112 °F — hotter than most hot tubs — which can cause overheating, dizziness and heat exhaustion, especially for children, the elderly and those with heart conditions; limit soak time, stay hydrated, and exit if you feel faint or overheated. Children require extra supervision; the pools are deep in places. The swimming complex water slides and diving boards carry their own impact risks; follow all posted rules. The Portneuf River tubing is fun but the river has rocks and mild rapids; tube with a life jacket if you are not a strong swimmer. Respect the heat of the mineral pools and the rules of each facility.

Separate per-person admission fees apply to the hot springs pools and the Olympic swimming complex. Shower before entering the mineral pools; no soaps, shampoos, lotions or sunscreen in the pools. Follow all pool rules (no diving in soaking pools, children must be supervised). The Olympic complex has its own rules for the slides and diving boards. Tubing the Portneuf is managed by local outfitters; follow their instructions and wear a life jacket. Pets are not allowed in the pool facilities. Check the Lava Hot Springs Foundation for current fees, hours and any reservation requirements — busy weekends may require pre-purchase of tickets.

The city of Pocatello (Idaho State University, the Gateway to the Northwest), the Portneuf River Greenway bike path, the Caribou-Targhee National Forest and the Caribou Range above town, Soda Springs (with its famous geyser and mineral springs), the Oregon Trail history of the region, and the greater southeastern Idaho high desert define the area. Lava Hot Springs anchors a corner of Idaho rich in geothermal and trail history, easily combined with Soda Springs’ curiosities and the historic Oregon Trail sites of the Portneuf Valley.

Buy your tickets online ahead of busy summer weekends — the pools and swimming complex can reach capacity and turn people away. Come midweek or in the shoulder seasons (fall and spring) for a more relaxed soak with smaller crowds, and consider a winter visit for the unique pleasure of soaking under a snowy sky. Shower before entering the mineral pools, limit soaks to 15–20 minutes to avoid overheating, and rehydrate with water. Add a tube float on the Portneuf in summer, stay in one of the town’s inns for a full relaxation weekend, and save the Olympic complex for a lively afternoon with the family.