Catholicism comes to the Pacific Northwest and Northern Rockies

Belgian Jesuit missionary Pierre Jean De Smet offered the first recorded Mass in what is now Wyoming in 1840 while traveling north to work among the Flathead people.

The Holy See established the Diocese of Cheyenne in 1887 to encompass the Wyoming Territory. Maurice Francis Burke, an Irish-born priest from Chicago, was appointed the first bishop. To serve the vast territory, Bishop Burke used the railroad to reach southern towns and stagecoaches or buckboards to visit northern communities. At the time of his appointment, the diocese was served by 6 priests, 21 women religious, and 1 lay brother.