Colome, Lower Brule, Bear Butte, Pine Ridge, and Belle Fourche are names unique to the Diocese of Rapid City, which encompasses 43,000 square miles in western South Dakota. Bounded on the east by the Missouri River, the prairies of the diocese are scattered with farms and ranches and small towns. The Black Hills, the highest mountain range east of the Rocky Mountains, runs along the western edge of the diocese.

More than 227,000 people live in western South Dakota. The largest city in the diocese is Rapid City, with approximately 60,000 people. More than 25,000 people in the diocese are Catholic, which is 11 percent of the total population. Twenty-seven percent of the Catholics in the diocese are Native American and ten percent are Hispanic.

Although there is at least one Catholic church or mission in all of the counties in the diocese, most of the priests travel long distances to serve two or three parishes. Currently, 28 diocesan priests, two extern priests, 17 religious order priests, and 28 deacons serve in 88 parishes/missions in the diocese. One priest is serving in the military. There are 39 religious women and 4 religious brothers serving in the diocese. Eight priests are retired or living outside the diocese.  Bishop Robert Gruss was ordained as the eighth bishop of the diocese on July 28, 2011.

Since its formation in 1902, the Diocese of Rapid City has been blessed with bishops who have had a vision for the growth of faith within the diocese. The first few bishops established permanent parishes throughout the diocese. Bishops who came later further shaped the mission of the diocese by establishing offices of religious education, faith formation, family life, and youth ministry, among others.

When Archbishop Charles Chaput was bishop of the diocese, a lay ministry program and an Office of Native Concerns were established and the vocations program was expanded. Under the direction of then-Bishop Blase Cupich, an Office of Inculturation was created to address the evangelization need of Native American Catholics in the diocese.

Programs in the diocese include a diocesan newspaper, Catholic Social Services, and the Sioux Spiritual Center, a retreat center for ministry formation participants staffed by Jesuits. The Catholic school system in the diocese consists of a grade school and a high school in Rapid City and a Jesuit school for grades K-12 on the Pine Ridge Reservation. There are two Newman Centers for college students in the diocese.

The mission of the Diocese of Rapid City is the threefold ministry of Jesus: to proclaim the Gospel; to build up the community of faith that is the Catholic Church; to reach out in love and service to those in need. As they seek to accomplish this mission, the bishop, clergy, religious and laity of the diocese all reflect the ministry of Jesus on earth.