For centuries Native Americans have been coming to these pure, flowing hot water springs for rest and healing. Legend tells that they called this area Peace Valley. They agreed to lay down their weapons when they sojourned here, believing that the land and the waters were for everyone to share and could not be owned. In the 1860s, prospector James Riley chanced upon the springs and filed a land and water rights claim. In 1864, he built a crude bathhouse and tavern. When Riley succumbed to smallpox in 1882, new owners built a small, more fashionable hotel. In 1891, it was remodeled and enlarged in the Queen Anne style and boasted fifty-two rooms, electricity, facilities for invalids, a resident physician, gymnasium, and various entertainments. Between 1910 and 1913, the present bathhouse, east wing and an addition at the west were built. The older building was also remodeled with raised parapets and a covering of stucco, creating a grand hotel in the present California Mission style. Opulent interior appointments included Tiffany glass lighting, beamed ceilings, and hand-stenciled walls in the Arts and Crafts tradition. Under various names and owners, Boulder Hot Springs has catered to a widely varying clientele. Architecturally significant as vintage Queen Anne remodeled to a newer style, Boulder Hot Springs is the last vestige of the many large-scale hot spring retreats that provided respite and recreation to early Montanans.