Located at the edge of Thermopolis, Hot Springs State Park was built around the world’s largest single mineral hot spring. Big Spring pours forth millions of gallons of mineral water every 24 hours at a constant temperature of 135 degrees Fahrenheit. The perpetual fountain forms a seething caldron from which some of the water is channeled into pools to be cooled and then piped into bathhouses for public use. From another stream, the water flows over enchanting Rainbow Terrace and then spills down into the Big Horn River.
Two swimming plunges and the State Bath House provide indoor and outdoor pools. Open year ‘round, the plunges offer mineral water swimming and all types of recreation equipment. A herd of buffalo roams the red hills behind the main portion of Hot Springs State Park.