[2] Wild Horse was developed in 1913 when a well driller hit 128 °F (53 °C) hot water, and has "private plunges, but little else.

[1][6] In 1941 Bartlett raised monies for a project named the Montana Warm Water Project for Crippled Children to construct a polio treatment center for children named Camp Aqua.

A public resort was later built in the early 1980s funded by a Montana renewable energy grant.

The mineral content of the water includes bicarbonate, calcium, carbonate, iron, manganese, magnesium, potassium, silica, sodium, sulfate, among others.

[1] The hot mineral water emerges from the source at 120 °F (49 °C) to 128 °F (53 °C), and cooles to 104 °F (40 °C) in the soaking pools and private plunges.