In 1884, Brondel purchased land in present-day Ashland to found the St. Labre Indian School, staffed by Ursuline Order sisters.

The second bishop of Great Falls was Reverend Edwin O'Hara from the Diocese of Oregon City, named by Pope Pius IX in 1930.

[14] O'Hara then promoted the establishment of CCD neighborhood groups of four to six adults to study a single work for eight weeks, twice a year.

To replace O'Hara, Pope Pius XII appointed Monsignor William Condon from the Diocese of Spokane.

[17] In 1978, Reverend Thomas Murphy of the Archdiocese of Chicago was appointed bishop of Great Falls-Billings by Paul VI.

To replace Murphy in Great Falls-Billings, John Paul II appointed Auxiliary Bishop Anthony Milone from the Archdiocese of Omaha.

[21] In 2005, the Northern Cheyenne Nation sued the St. Labre Indian School in Ashland and the Diocese of Great Falls-Billings.

However, the Supreme Court did say that the Northern Cheyenne had failed to prove allegations of breach of contract, negligent misrepresentation, fraud and wrongful conversion.

Critics accused the diocese of trying to protect the church's assets from victim claims by transferring them to an organization it controlled.

[25] In March 2017, the diocese filed for Chapter 11 bankruptcy in the light of multiple lawsuits for sexual abuse of minors by clergy.

The priests, wearing clerical garb, had attended a political rally in Great Falls for President Donald Trump.

[26] In March 2017, just weeks before the first sexual abuse trials were to begin,[27] the diocese filed for Chapter 11 bankruptcy.

They alleged that the diocese illegally triggered its bankruptcy by creating CASC, in what they termed as a fraudulent attempt to hide $16 million assets.

In addition, the Great Falls-Billings plan also required the diocese to begin "intensive background checks and screening of potential seminarians" and to publish a list of all known abusers, past and present, that were named in the lawsuits.

[36] The $20 million was to come from the following sources: In November 2018, Reverend Lothar Krauth, a retired priest from Our Lady of Lourdes in Great Falls, was arrested on charges of possessing child pornography.

Receiving a tip from the US Department of Homeland Security, local police found thousands of images of young children engaged in sexual activity.