Thermopolis is a town in Northwest Wyoming, USA, notable for the presence of one of the world’s largest hot springs. It has a population of around 3,000.
Thermopolis is located near the northern end of the Wind River Canyon, by the Bighorn River and is surrounded by mountains, with the Bridger Mountains to the southeast, the Owl Creek Mountains to the southwest, the Big Horn Mountains to the northeast and the Absaroka Range to the northwest.
The Downtown Thermopolis Historic District comprises Main Street, Broadway, and Fifth Street. The buildings lining the street were built between 1898 and 1923 in styles ranging from adaptations of commercial style to Victorian. Broadway, as implied by its name, was built wide enough to accommodate teams of 16 mules or horses. The Downtown Thermopolis Historic District was listed on the National Register of Historic Places in 1984.
One of the main downtown attractions is the Hot Springs County Museum and Cultural Center which has an eclectic collection of memorabilia from local pioneers circa 1890 through 1910, with a particular focus on Tim McCoy, who lived in Hot Springs County from 1912 to 1942. He worked for many years as an actor in what are now called B westerns, or lower-budget cowboy movies in Hollywood.
Hot Springs State Park is home to several bathhouses where you can relax in the mineral-rich hot springs, have a picnic, go on a hike, or go for a drive.
The hot springs were formed via geothermal heat. Below the Earth’s surface there is magma which generates heat. Hot Springs State Park has a network of faults and fractures in the Earth. When rainwater or snow deeps in the Earn through these faults, it comes into contact with the hot rocks and the heated water rises back to the surface through these faults. When it reaches the rock layers on the surface, it is forced to flow laterally until it reaches the surface. At that point is when the hot springs are formed.
Big Spring is the world’s largest mineral hot spring, discharging over 18,000 gallons of water every 24 hours at a constant temperature of 135 degrees Fahrenheit.
You can see the terraces that formed from the cooling of the water as it flowed over the surfaces and these continue to show the geological history in this park.
The Rainbow terraces show an array of colors due to the presence of different types of thermophilic bacteria and algae that thrive in the warm water, creating a visually striking natural phenomenon.
In 1897, as part of the original agreement with the Eastern Shoshone and Northern Arapaho tribes, the land was sold to the federal government, and with that, access to the mineral hot springs would remain free.
Native Americans believed that the water, maintained at 104 degrees, contained therapeutic healing powers. Many visitors and locals soak in these waters as part of their visit to Thermopolis. Guests can soak in either indoor or outdoor springs for 20 minutes at a time, up to three times a day.
Take a walk on one of the many easy trails in Hot Springs State Park. The suspension foot bridge across the Bighorn River provides a vantage point where you can see beautiful views of the river as well as of the mineral terrace.
The Wyoming Dinosaur Center opened in 1995, when a fossil collector Burkhard Pohl vacationed in Wyoming and discovered dinosaur bones in the area. The museum features over 30 mounted skeletons, information about the rise and fall of dinosaurs and a unique opportunity to tour a nearby live dig site, where they are still uncovering bones today.
Legend Rock Petroglyph Site is located 30 miles out of Thermopolis. This site features 55 separate rock panels with several hundred petroglyphs and a few pictographs dating back over 10,000 years.