[5] He studied for the Archdiocese of San Francisco, possibly inspired by the example of Eugene O'Connell, an All Hallows professor who had been recruited by Archbishop Joseph Sadoc Alemany in 1850 and made Vicar Apostolic of Marysville in 1860.

[8] In early 1873, he briefly returned to California to serve as pastor of St. Vincent's Church in Petaluma, where one of his parishioners was the grandfather of Scanlan's future successor William Weigand.

[4] Scanlan remained at Petaluma until the summer of 1873, when Archbishop Alemany appointed him to missionary work in the Utah Territory, which had been entrusted to the Archdiocese of San Francisco two years earlier.

[12] In April 1885, the Deseret News praised Scanlan for refusing to sign a petition to President Grover Cleveland calling for restrictions on the LDS Church.

[9] By 1886, the growth of Catholicism in Utah was sufficient to lead Patrick William Riordan, Alemany's successor as Archbishop of San Francisco, to request that the Vatican erect an apostolic vicariate, essentially a provisional diocese with its own bishop.

[9] With the approval of Pope Leo XIII, the Congregation for the Propagation of the Faith established a vicariate to cover the entire territory of Utah and parts of eastern Nevada.

[7] He received his episcopal consecration on the following June 29 from Archbishop Riordan, with Bishops Eugene O'Connell and Patrick Manogue serving as co-consecrators, at St. Mary's Cathedral in San Francisco.

"[9] Scanlan eventually agreed to accept an auxiliary bishop and arrangements were made for the appointment of Joseph Sarsfield Glass, a Los Angeles priest.