As the first Bishop of the Diocese of Helena, Bishop John Baptist Brondel formed a solid foundation upon which all of the succeeding bishops would build. He traveled the state extensively bringing the Word of God to the frontier settlements. He established parishes and built churches. His greatest achievement was in the area of the clergy where he increased the number of secular priests significantly. By 1903, he had increased the number of young men preparing for a priestly life in Montana from one to 13.
Prior to his death, Bishop Brondel petitioned the Holy See for the division of his diocese due to the difficulties involved in traveling the entire state. His request was approved and on May 18, 1904, the Diocese of Great Falls, covering the eastern two-thirds of the state, was erected. Bishop Brondel died November 3, 1903, and was succeeded by John Carroll as second Bishop of Helena.