Star Plunge Hot Springs, Wyoming: Thermopolis Soaking Guide

What Star Plunge is and where it sits

Star Plunge is a concession facility inside Hot Springs State Park in Thermopolis, a central Wyoming town built around its mineral water. It sits along the Bighorn River corridor, near the terraces and the network of trails that make the park a full-day destination rather than a quick roadside stop. Because it operates inside the state park, the pools and their availability are tied to the park's management rather than to a stand-alone spring.

The park itself covers about 1,100 acres on the banks of the Bighorn River, with trails, playgrounds, picnic areas and two hotels inside its boundaries, according to reporting on the facility's management dispute. Wyoming State Parks describes it as a day-use area with 6.2 miles of universally accessible trails and hiking trails. That layout means you park once and walk between the soaking options, the swinging bridge and the river overlooks.

The Star Plunge has been a Thermopolis institution since the Luehne family took over the concession in 1975, and it became a fixture on family itineraries for generations. Its future came under a legal cloud when the state selected a new concessionaire and the longtime operator sued in 2024. Wyoming State Parks has since announced a tentative agreement for Star Plunge operations, so treat the pool as part of a park visit and look to the park's news updates for what is running on your dates.

Why Thermopolis draws soakers

The attraction here is volume and spectacle as much as temperature. More than 1.8 million gallons of mineral water flow over the terraces every 24 hours at a constant 128 degrees Fahrenheit, which is why the terraces steam in cold weather and draw photographers year-round. That source water is far too hot for bathing, so the soaking happens in the managed pools that cool it to a comfortable range.

The free bath house that the state runs is the clearest example of that cooling: water there is maintained at 104 degrees for therapeutic bathing. The contrast between the scalding source and the tempered soak is the story of the park, and the mineral terraces along the river make the walk between pools worth taking slowly. Wyoming Tourism points to the rainbow terraces, the state's bison herd and the swinging bridge as reasons to linger.

The pools at Star Plunge

Star Plunge is a developed aquatic facility rather than a natural soak, with slides and several pools built for recreation and family use. It has historically offered both swimming and soaking in a setting that feels like a community pool with a hot springs pedigree, and it draws families who want the kids entertained while adults sit in the warm water. For a quiet, meditative soak, the other options in the park suit better.

The facility also functions as a gateway to the state park's scenery, since the terraces and river trail are just outside. Plan the pool as one part of the visit rather than the whole visit: soak, then walk the terraces and the swinging bridge while the warmth wears off. Bring a towel regardless of which pool you choose.

The other soaks in the park

The State Bath House is the simplest way to soak in Thermopolis. It is a free public facility with an indoor soaking pool and an outdoor soaking pool, and soakers have historically been limited to 20 minutes per session. Summer hours run Monday through Saturday 8 a.m. to 7 p.m. and Sunday noon to 7 p.m., and winter hours shorten the close to 5:30 p.m.; the bath house is closed Thanksgiving and Christmas Day. Hours and pool access change with construction and season, so read the park's posted notices at the door.

Tepee Pools, also called Hellie's TePee Pools, is the second commercial soaking option in the park, with slides and several pools of its own. When Star Plunge was dark during the management dispute, visitors crowded into the Tepee, so on peak weekends expect a busier changing room and pool deck there. Wyoming Tourism keeps both names on its hot springs listings for the Thermopolis area.

Getting there

Hot Springs State Park sits at 51 US Highway 20 North in Thermopolis, which puts the pools within a short drive of downtown motels and restaurants. US 20 runs through town along the Bighorn River, and the park entrance is signed, so you do not need a forest road or high-clearance vehicle to reach the soaking areas. Once inside, park in the central lots and walk the trails and sidewalks between the facilities.

From the park grounds you can connect more than six miles of trails, including a universally accessible stretch, to the swinging bridge, picnic shelters and the river overlooks. That network makes it easy to build a half day around the pools without moving the car. The park grounds open early and close in the evening, with gates locked outside posted hours.

Fees and hours

The State Bath House charges nothing and is operated by Wyoming State Parks, making it the lowest-cost soak in the park. Star Plunge and Tepee Pools are concession businesses, and their admission is paid on site through each operator, so bring a card or cash and confirm the day's rate at the counter. The bath house summer hours run 8 a.m. to 7 p.m. Monday through Saturday and noon to 7 p.m. Sunday, with winter hours ending at 5:30 p.m.; both change with construction and season.

Watch for construction notices: in August 2026 the park closed the outdoor soaking pool at the State Bath House for about a month to install a pool lift, new handrails and sidewalk heating, while keeping the indoor pool open. The same work adds winter usability, so the outdoor pool is worth retrying on a cold-weather trip. Check the park's news page before you drive for pool-by-pool updates.

Rules and etiquette

At a developed pool like Star Plunge, follow the posted rules on slides, flotation devices, glass, alcohol and children in the water. The state park is a day-use area with no overnight camping, so plan your soak as a daytime stop rather than a place to sleep. Picnic shelters are reservable, and the park asks groups to inquire about liquor permits for events.

Two practical cautions apply across all three pools. The terraces and pool decks get slick, so wear shoes with grip and move slowly near the water, and never submerge your head in untreated geothermal water. These are habit-level moves, not warnings that should color the whole day.

Best time to go and how crowds shift

Summer is the park's busiest season, when the terraces, picnic grounds and all three soaking options run at full tilt. The bath house's posted hours are longest in summer, which opens early-morning and evening soak windows around a day of hiking or driving. Locals treat the bath house as a lunchtime ritual, so expect a lunchtime bump on weekdays.

Off-season visits trade long daylight for shorter pool hours and the chance to see the terraces steaming against cold air. The park's bison herd is fed a supplement at 8:30 a.m. in late fall and winter, giving off-season visitors a reliable moment to view the animals from the vehicle. Stay in the car: the park is explicit that bison should be viewed only while you remain in your vehicle.

Camping and lodging

Hot Springs State Park does not offer overnight camping, so base yourself in Thermopolis and walk or drive in for the day. The town has motels along the main highway and two hotels inside the park grounds, which puts the pools and the swinging bridge within a short walk. When Star Plunge was dark during the management dispute, lodging operators reported cancellations from families who came specifically for that pool, so book around the full park experience rather than a single facility.

For a longer thermal circuit through the state, the town makes a sensible first or last stop. Fit the park into a wider route of hot springs to compare a developed pool day with a primitive soak. The free bath house makes an easy, low-cost addition to any Thermopolis stay. If your route runs beyond Wyoming, a Utah guide offers another set of developed resorts and wild soaks to compare against Thermopolis.

Nearby springs and road-trip combos

The best complementary stop is a primitive hike-in soak, which balances the developed pools at Thermopolis. Polecat Hot Springs in Wyoming is a hike-in soak that requires a short approach and your own supplies, a striking contrast to a concession pool with slides. Pairing the two lets you experience both ends of the Wyoming hot springs spectrum in one trip.

If you are heading toward Jackson, the walk to Huckleberry Hot Springs along the Sheffield Creek Trail is a classic Wyoming soak near Flagg Ranch. Collect that kind of trail soak in summer and keep the Thermopolis pools for a cooler season. It is all part of the same road-trip map of Wyoming hot springs.

On long drives you will pass Saratoga, where Saratoga Hot Springs offers a town-park soak, and Jackson, where Astoria Hot Springs Park pairs a developed pool with a riverside setting. These make natural overnight pauses on a Wyoming hot springs loop. Plan for shorter days in winter, when mountain passes can add hours.

Leave No Trace at wild soaks

If you extend the trip into a primitive hot spring, pack out everything you bring and leave the site cleaner than you found it. Keep soap, food and trash out of the water, and stay on established paths to protect the surrounding vegetation. At developed pools such as the Tepee Pool and Fountain of Youth in Hot Springs State Park, the posted pool rules stand in place of backcountry etiquette, so check current hours and prices before you go.

Plan Your Thermopolis Soak

Thermopolis rewards travelers who treat the hot springs as a park day rather than a single pool stop. Compare the free bath house, the Star Plunge and the Tepee, then build in the terraces, the bison herd and the swinging bridge. Check conditions with Wyoming State Parks before you drive, especially when construction or concession changes are in play, and the rest of the planning is straightforward. For every soak in the state, start with our guide to Wyoming hot springs.