Feeling frazzled? These soothing hot springs let you unwind

You can spot the puffs of steam about a hundred yards up the trail from Idaho’s Jerry Johnson Hot Springs, the kind of ethereal gray mist that might engulf a fantasy movie dragon or wizard. Hikers and day-trippers head to this section of the Nez Perce-Clearwater National Forest for a sort of natural magic: a soak in bubbling hot springs rock pools surrounded by clumps of cedar trees, craggy mountains, and, in summertime, blankets of wildflowers.

Humans have been wading into such naturally heated waters for millennia. Ancient Romans created a spa town around the thermal springs of what’s now known as Bath, England; North American Indigenous people dipped into springs for health and ceremonial purposes.

“There are many legends and stories about how soaking in hot springs can cure your ills or change your life,” says Montana-based geothermal energy specialist Jeff Birkby. “But really, just sitting under the stars in hot water comes with its own benefits.”

In the United States, you’ll find thermal springs in the wilderness at so-called “primitive” or “rustic” soaking holes, at no-frills bathhouses, and in spas which divert or harness the waters into fancy one-person bathtubs or jumbo swimming pools. The latter are often centered in historic towns that have sprung up around the traditional of therapeutic bathing. Here’s a dive into why and where America’s hot springs bubble up, plus how to try them for yourself.

How do hot springs happen?

Around the world, hot springs occur when fissures or fractures in the ground allow rainwater or snow melt to seep down into the earth’s magma. There, it’s heated, eventually circulating back to the surface as a warm-to-boiling water. Sometimes these thermal springs are powered by active volcanic activity; others pop up along fault lines or other breaks in the earth. Geysers, such as the ones at Yellowstone National Park, happen due to a similar phenomenon, but they periodically erupt whereas springs flows continuously.

(Learn why some geysers are becoming more active.)

There are at least 1,664 known hot springs in the U.S., most of them in Western part of the country in states including Idaho, Nevada, New Mexico, and California. “The earth’s crust is generally thinner in the West, and there’s simply more seismic and volcanic activity. This creates deep fractures or faults and provides local sources of intense heat,” says Duncan Foley, a Washington State geologist and author of Yellowstone Geysers: The Story Behind the Scenery. In the East, springs primarily occur in the Appalachian Highlands where rocks “folded” by seismic activity allow water to get in and out.

In the U.S., it’s easy to find both “primitive” (aka undeveloped) hot springs and commercial ones that have been turned into spas: There’s an interactive map of all of them on the National Oceanic and Atmospheric Association website, the descendent of a cataloguing project done for the Works Progress Administration during the 1930s.

This ability to pinpoint the locations of nearly every hot spring in the country has been both a boon for soakers and an invitation for overuse at the primitive sites.  “And now, with social media and internet, there are no secret hot springs left in the Western U.S.,” says Birkby. “Everyone has a GPS and a guidebook.”

Primitive soaks in nature (and au naturel)

Whether they’re on private or public land (state or national parks, U.S. Forest Service spaces), primitive hot springs can suffer from the same sort of overtourism as recreational sites like hiking trails or campgrounds. Soakers wear down surrounding vegetation with foot traffic, contaminate the water with E. coli by defecating too close by, and leave trash in or around pools (broken beer bottles are a major problem). 

“You’re not going to a hot tub party in the woods,” says Janet Abbott, the board president of the Balneology Association of North America (BANA), a thermal water education and research group. “Soakers need to be as low-impact as they can and pack in and pack out.”

There are signs that good management is helping many springs stay pristine. In Colorado’s Maroon Bells-Snowmass Wilderness, camping around the popular Conundrum Hot Springs has been limited by a strict permitting system since 2017. Campers and hikers are also required to either bury their solid waste 200 feet from the water or, preferably, pack it out using a W.A.G. bag, a techier, larger version of what you’d use to dispose of your dog’s poop.

(Chill out—and heat up—at these Colorado hot springs.)

At Jerry Johnson Hot Springs, the U.S. Forest Service has responded to increased visitation by installing a vault toilet at the trailhead, making the springs day-use only (which discourages partying and littering), and by diverting horse trails away from the waters. “We’ve seen the impact level reduced, and saplings have started to come back,” says Brandon Knapton, the ranger overseeing the area. “It’s a balance of protecting the natural resources and giving people a social experience.”

Besides planning to leave no trace, a dip in a primitive hot spring requires little more than a bathing suit or birthday suit, since many pools are clothing-optional. “Research the area you’re going to—the water temperatures, the policies,” says Abbott. “You want to find out whether you’re on public or private land, then be respectful of other people.” Bring some drinking water, too, since a soak can leave you dehydrated.

Why take the plunge?

The mineral water coming out of hot springs ranges from warm to boiling, like the pretty mineral pools in Yellowstone that would literally cook any person or beast that jumps into them. The safest and most comfortable range for humans is 104 to 106 degrees Farenheit.

Both that warmth and the springs’ mineral content have lured soakers for hundreds of years. On its way back up to the earth’s surface, heated water comes into contact with substances including calcium, lithium, and even arsenic, lending soaking pools a high mineral content and, sometimes, a distinctive, rotten-eggy, sulfur smell. The fast flow rate of the springs assured that the waters usually don’t require chlorine to remain safe for bathers, though modern commercial bathhouses are often required to use it.

Both proven (back-pain relief) and folkloric health benefits (Banish gout! Look younger!) of steeping in those minerals are part of the allure. “There are elements of myth and awe surrounding bathing, this healing relationship between you and the waters,” says Marcus Coplin, an Oregon-based naturopathic doctor and BANA board member. “In Europe, the established hot springs spas have doctors on staff and consider the process a medical treatment.”

Spa towns bubble up

From the late 18th century until around World War II, the perceived medical benefits and indulgent pleasures of taking a water “cure” fueled the development of spa towns across America. They ranged from simple “cowboy” soaking havens like Thermopolis, Wyoming to swanky resorts towns that bubbled up around springs, such as Calistoga, California, still famed for its hot, volcanic mud baths. 

“People would travel to these hot springs towns by train or stagecoach, and the destinations created hotels, casinos, and other recreation to cater to the crowds,” says Abbott.

(Why—and how—to save a historic hotel.)

Entrepreneurs then and now either built simple cement or rock pools outdoors and diverted existing waters into them (e.g., small, river-side outdoor spas in Truth or Consequences, New Mexico) or jumbo-sized heated swimming pools (Evans Plunge in Hot Springs, South Dakota). Fancier spas and resorts created mineral water-fed bathtubs for one. 

“The idea was that different spring sources or mineral were good for different parts of the body, like go into this pool to help foot ailments or that pool to deal with your aching back,” says Tom Hill, the museum curator at Hot Springs National Park in the town by the same name in Arkansas. “People were coming by the thousands and staying for a few weeks or month to soak and even drink the water.”

The park, celebrating its centennial with the National Parks Service in 2021, encompasses both creek-filled wilderness and the grand Bathhouse Row, where eight spa buildings erected between 1892 and 1923 remain. 

These architectural confections—in styles like Italian Renaissance and Spanish Revival—pay tribute to the booming wellness industry of an earlier America. The 1915 Fordyce Bathhouse serves as a history museum and park visitor center, while the domed Quapaw Baths and Spa and the Buckstaff Bathhouse both still operate spas.

“There’s a core group of bathers that never stopped soaking in springs, even with modern medicine or the COVID-10 pandemic,” says Hill. “People do what they’ve always done—come to town, bathe in the waters, drink them, and relax in the clean air. Whether you’re cured of anything or not, you head home feeling better.”