Hot Springs State Park
Hot mineral water builds living travertine terraces beside the Bighorn River, where a free public bath house and a drive-through bison pasture make geology unusually tangible.
Artwork inspired by Travis Ivey
Big Spring and White Sulphur Spring are the park’s two active springs. Water heated at depth reaches the surface near 130°F; as it cools, dissolved calcium carbonate precipitates into travertine. Warm-water algae interacting with the minerals produces the terraces’ cream, orange, green, and brown bands, while older dry deposits show where the springs flowed in the past.
Walk the mineral terraces before soaking so the plumbing makes sense: spring water is routed across the deposits and into bathing facilities. The State Bath House cools it to 104°F and offers free 20-minute sessions, while separately operated commercial pools have their own prices and features. The 1916-era Swinging Bridge, rebuilt in 1992, gives the clearest elevated view across the Bighorn River to the terraces.
A road through the park’s fenced pasture offers a second, very different experience. Wyoming State Parks maintains a year-round bison herd here, with calves commonly arriving from April through June; sightings are likely but never guaranteed. Remain inside the vehicle around bison, and plan lodging or camping elsewhere because the park has no overnight campground.
- Big Spring
- About 2,900 gallons per minute at 127°F
- Public soak
- Free, 104°F, 20-minute sessions
- Bridge
- Built in 1916; replaced in 1992
Quick guide
- Begin
- Follow the terrace boardwalk while the light reveals active wet flow and older dry deposits.
- Do not miss
- Use the free State Bath House for a quiet 104°F soak; commercial pools are separate.
Separate the free indoor soak from the closed outdoor pool
- Terraces
- Walk the boardwalk first to see how hot mineral water cools, deposits travertine, and feeds changing bands of color.
- Indoor bath
- Use the free State Bath House for a 20-minute 104°F session during its corrected 7 p.m. closing schedule.
- Outdoor pool
- Treat the construction reopening as provisional until the park confirms the new lift, concrete, and handrail work is complete.
- Bison loop
- Remain inside the vehicle, keep traffic moving, and view the herd without treating a sighting as guaranteed.
Good to know
The free bath house and any outdoor pool can have different operating status and hours. River cyanobacteria advisories concern river exposure and do not automatically describe the managed bath; confirm both notices before entering water.
Notice these
- Living travertine terraces
- Free 104°F indoor soak
- Bighorn River and bison loop