 At that time, his vicariate (which comprised the greater part of what is now Colorado, the Dakotas, Kansas, Montana, Nebraska, and Wyoming) contained five churches, eight priests, and 5,000 Catholics.In 1851 he erected the first Catholic church in Kansas, St. Mary's of the Immaculate Conception in Leavenworth, which he also designated as his cathedral.Miège conducted extensive pastoral visitations throughout the wild and remote regions over which his congregation was scattered, visiting the Indian villages, forts, trading posts, and growing towns and celebrating Mass on the rear end of his wagon.