Montana

Pierre-Jean De Smet, the Belgian Jesuit who led the mission Salish and Pend d'Oreille leaders had specifically requested, founding St. Mary's Mission in the Bitterroot Valley in 1841 as the first sustained Catholic mission in the Rocky Mountain West, did not spend his career only ministering to the communities that had invited him. His fluency in Native languages and the trust he had built across the northern plains made him useful to the federal government in a very different role, and he served as an intermediary in major treaty negotiations, including the 1851 Fort Laramie Treaty that attempted to define territorial boundaries among the Plains nations, and later peace missions carrying messages to Sitting Bull's Lakota in 1868 when few other white negotiators could gain an audience at all. De Smet's dual role, missionary to some tribes and diplomat trusted by others he had never evangelized, reflects how thin the line between religious and political authority actually was on the era's frontier.

Hutterite communities, an Anabaptist sect holding all property in common and living in self sufficient agricultural colonies, settled across eastern Montana in the twentieth century and remain among the largest concentrations of Hutterites in North America, a communal tradition with no connection to De Smet's Catholic missions. The Blackfeet, Crow and other Montana tribes maintain distinct ceremonial and Sun Dance traditions on their reservations today. Evangelical Protestant identification leads the state at twenty eight percent of adults, per Pew's 2023-24 study.