Hot Springs State Park

Hot Springs State Park is a public recreation area in Thermopolis, Wyoming, known for its hot springs, which flow at a constant temperature of 135 °F. The state park offers free bathing at the State Bath House, where temperatures are moderated to a therapeutic 104 °F. The petroglyph site at Legend Rock, some 25 miles away, is also part of the park. The park is managed by the Wyoming Division of State Parks and Historic Sites.

Source: Wikipedia