In 1776 the expedition of two Spanish Franciscan priests generated the first heartbeat of Catholicism in Utah. Francisco Atanazio Dominguez and Silvestre V. de Escalante left Santa Fe in search of an overland route to Monterey. They circled northward through Colorado, Utah, and Arizona before returning to New Mexico, the first known non-Native Americans to enter the land that became Utah. Traveling without military escort, they bridged the cultures of white man and Native American and drew the first maps ever made of Utah. A thirty-seven-foot steel cross stands today in Spanish Fork Canyon to mark their entry into Utah Valley on 23 September 1776.

At the turn of the century, in the era of the mountain men, Catholic hunters and trappers who cut trails across Utah included Antoine Leroux, the five Sublette brothers, and Lucien Fontenelle. Etienne Provost is believed to be the first non-Native American to view the Great Salt Lake. Thomas Fitzpatrick of the Rocky Mountain Fur Company became the first government agent for Indian tribes. Jean Batiste Chalifoux in 1835, Antoine Robidoux in 1837, and Denis Julien in 1831 and 1836 recorded their presence in Utah in petroglyphs carved in rock near their campsites. The cross etched in stone by Kit Carson in 1843 can still be seen on Fremont Island in the Great Salt Lake.

In 1850 the Holy See in Rome assigned ecclesiastical responsibility for Utah Territory to the Diocese of Monterey but altered diocesan boundaries in 1853, placing Utah under the Archdiocese of San Francisco, whose domain extended eastward to the Colorado River. By 1866, however, the care of Utah was shifted to the Vicariate of Marysville, which later became the Diocese of Grass Valley. A Vicariate of Colorado-Utah formed in 1868 proved too extensive to cover, and in 1870 jurisdiction over Utah reverted once again to San Francisco.

During this period of administrative uncertainty, missionaries Father Jean Batiste Raverdy from Santa Fe and Father Toussaint Mesplie from the Archdiocese of Oregon City visited Utah. Bonaventure Keller of Philadelphia offered the first known mass in Utah in July 1859 at Camp Floyd. Father Edward Kelly came from San Francisco in 1866 and purchased the first Catholic Church property in Utah. Bishop Joseph P. Machebeuf and Father John V. Foley journeyed to Salt Lake from Colorado in 1868 and 1870 respectively.

The heartbeat of Catholicism in Utah strengthened with an influx of miners and railroad workers drawn by the discovery of mineral wealth in 1863 and the completion of the transcontinental railroad in 1869. The mining activities of General Patrick Edward Connor, founder of Fort Douglas, attracted a growing number of non-Mormons. In 1873 Archbishop Joseph S. Alemany of San Francisco entrusted the approximately 800 Catholics among Utah's 87,000 inhabitants to Father Lawrence Scanlan (1843-1915).

Though fluent in French, German, and Italian, Scanlan symbolized an Irish influence in the pioneer community. He built churches, schools, and hospitals in railroad junctions and mining camps: Salt Lake City and Ogden in 1875, Silver Reef in 1879, Frisco and Park City in 1881, and Eureka in 1885. Miners who struck it rich often helped provide financial support. The Pious Fund, established in 1697 by the Society of Jesus for missionary lands, provided additional funding.

On 23 November 1886 Rome created the Vicariate of Utah and Eastern Nevada and appointed Scanlan bishop. He was consecrated at St. Mary's Cathedral in San Francisco on 29 June 1887. The vicariate developed into the Diocese of Salt Lake City on 27 January 1891 and still included seven counties in eastern Nevada. The new diocese numbered 8,000 in population and included fifteen churches cared for by fourteen priests.

Scanlan established an official newspaper, The Intermountain Catholic, in 1899 and founded missions and parishes throughout the state. Diocesan organizations such as the Knights of Columbus also began to form. Holy Cross Hospital, All Hallows College, Kearns-St. Ann's Orphanage, and Judge Mercy Home and Hospital served a growing Catholic community in Salt Lake City. On 15 August 1909 thousands attended the dedication of the Cathedral of St. Mary Magdalene. Six years later Bishop Scanlan died.

His successor, Joseph S. Glass, CM (1874-1926), decorated the interior of the cathedral and renamed it the Cathedral of the Madeleine. His tenure was followed by that of Bishop John J. Mitty (1884-1961), later Archbishop of San Francisco, who reorganized the diocese and stabilized its economy. On 27 March 1931 Rome removed the eastern Nevada counties from the diocese, declaring its boundaries contiguous with those of the state of Utah.

Bishop James E. Kearney (1884-1977) brought national renown to Utah as a missionary entity of the American Catholic Church. The writings and radio addresses of Bishop Duane G. Hunt (1884-1960), fifth bishop of the diocese, kept Utah Catholics in the national spotlight.

Bishop Joseph Lennox Federal (1910- ) attended sessions of the Second Vatican Council in Rome during the years from 1962 through 1965. He helped steady his people through the upheaval of change that followed the council, and also updated diocesan life and liturgy in accordance with its directives. The appointment of Bishop William K. Weigand (1937- ), upon the retirement of Bishop Federal in 1980, expressed the sensitivity of the American Church to issues of social justice. Bishop Weigand's service as a pastor in Cali, Colombia, for nearly a decade helped form his present concern for the Spanish-speaking and other minorities. With 90 priests, 95 women in religious orders, and an increasing number of lay men and women appointees, his successor will guide a diocese of more than 70,000 Catholics into the second century of its existence.