Thermopolis Hot Spring State Park

## Overview Hot Springs State Park in Thermopolis, Wyoming, is home to one of the world's largest mineral hot springs — Big Spring — which flows at an estimated 3.6 million gallons per day. Nestled along the banks of the Big Horn River, the park offers free public soaking in naturally heated mineral pools, making it a beloved destination for families, road-trippers, and hot spring enthusiasts alike. The hot springs carry deep cultural significance. In the latter part of the 19th century, the Eastern Shoshone and Northern Arapaho tribes ceded the hot springs to the state of Wyoming through a treaty negotiated in 1896. A key stipulation of the agreement, championed by Chief Washakie of the Eastern Shoshone, was that a portion of the hot springs would remain free to the public forever. That promise endures today — the State Bathhouse offers complimentary soaking year-round, honoring Chief Washakie's vision. For centuries before European contact, the mineral-rich waters were valued by Indigenous peoples for their reported healing properties. The springs' reputation as a place of wellness and restoration has persisted through the generations. ## Directions 1. The park is located at the north end of the town of Thermopolis, Wyoming, along US Highway 20 (also signed as WY-789). 2. From downtown Thermopolis, head north on US-20/WY-789. The park entrance and signage will be clearly visible on the east side of the road. 3. Once inside the park, follow the main road to the State Bathhouse and free soaking pools. Parking is available near the bathhouse and along the scenic loop drive. 4. GPS coordinates: **43.6553, -108.2021** — the address is listed as 42 US Hwy 20, Thermopolis, WY 82443. ## What to Expect **Free Soaking at the State Bathhouse:** The Hot Springs State Park Bathhouse features two indoor soaking pools maintained at approximately 104°F, fed directly by the natural hot spring. Outside, cooling ponds connected by wooden plank walkways allow you to adjust your soaking temperature. The outdoor pool, also around 104°F, includes cement benches for sitting and relaxing. There is no charge to use the State Bathhouse — a rarity among hot spring destinations. **Big Spring & Travertine Terraces:** A short walk from the bathhouse brings you to Big Spring itself, where steaming water emerges from the earth and cascades over vivid travertine mineral terraces. The terraces display striking bands of orange, white, and gold created by mineral deposits and thermophilic bacteria. Wooden boardwalks and paths wind through the terraces, offering excellent vantage points. **The Swinging Bridge:** One of the park's most photographed landmarks is the Swinging Bridge, a pedestrian suspension bridge spanning the Big Horn River. Originally built to connect Big Spring and Fremont Springs with the Pleasant View Hotel, the Sanitarium, the elk pasture, and Fremont Spring, the bridge also provided access to Hopewell Hospital — the first hospital in Hot Springs County. After years of deterioration, the original bridge was demolished by the Wyoming National Guard in 1991. In 1992, the North Dakota National Guard rebuilt it. According to interpretive signage at the bridge, it was constructed from scrap metal by a mechanic with no formal bridge-building experience, and its design was inspired by San Francisco's Golden Gate Bridge. Today, the bridge offers wonderful photo opportunities and a unique perspective of the river and surrounding landscape. **Bison Herd:** A scenic loop drive through the park passes through a pasture where a resident herd of bison roams the rolling Wyoming hills, much as they have for centuries. Visitors can often spot the herd grazing on the hillsides. Enjoy them from a safe distance — bison are wild animals and can be unpredictable and defensive. **What to Bring:** Bring a swimsuit, towel, and a change of clothes. The bathhouse provides changing rooms. The park is well-maintained and notably clean; visitors are encouraged to help keep it that way for future guests. **Seasonal Notes:** The State Bathhouse is open year-round, though hours may vary by season. Soaking in the steaming outdoor pools during winter, with snow on the surrounding hills, is a particularly memorable experience. Whether you're stopping for a quick soak on a cross-country road trip or spending a full day exploring the terraces, the bison pasture, and the Swinging Bridge, Hot Springs State Park in Thermopolis is a remarkable — and remarkably free — natural treasure.