Wyoming

The Sun Dance the Eastern Shoshone and Northern Arapaho still hold each year on the Wind River Reservation was, for roughly half a century, a federal crime. The Office of Indian Affairs issued the Religious Crimes Code in 1883, establishing Courts of Indian Offenses with authority to prosecute Native ceremonial practices the federal government judged incompatible with assimilation policy, and the Sun Dance, alongside other Plains ceremonies, was explicitly named among the practices reservation agents were instructed to suppress. Enforcement continued through the early twentieth century until the Indian Reorganization Act era reforms of the 1930s, driven by Commissioner of Indian Affairs John Collier, eased the assimilationist pressure that had underwritten the ban, and ceremonies that had continued quietly through the suppression years began resuming more openly on reservations across the northern plains. Federal protection was not fully secured until much later still, the American Indian Religious Freedom Act of 1978 establishing, nearly a century after the original ban, that the federal government would protect rather than prosecute Native religious practice.

Mormon settlers extended into western Wyoming from Utah and Idaho in the late nineteenth century, particularly around Star Valley, a very different nineteenth century religious settlement from the ceremonial tradition the federal code targeted at the same time. Wyoming's low population and dispersed ranching communities have left it with a comparatively thin institutional religious presence otherwise. No single tradition dominates the state today, Nothing in Particular narrowly leading at twenty four percent of adults over Evangelical Protestant at twenty three, per Pew's 2023-24 study.