This photo by Les Jorud likely dates from the late 1920s.

St. Mary's, in Helena's Sixth Ward, was designed by Albert O. Von Herbulis, the architect who also designed the Cathedral of St. Helena and St. Charles Hall on the Carroll College campus. This modest, straighforward design is certainly a departure from the styles of those two buildings.

The 1935 earthquakes badly damaged many Sixth Ward buildings, including St. Mary's. Initial assessments of the damage were that the church was damaged beyond repair, and had to be rebuilt. Ultimately, extensive repairs were undertaken. The church's shattered brick veneer was removed and replaced with "composition material".

As if that wasn't enough, in January of 1937 a fire broke out in the sacristy of the church, causing the loss of numerous vestments and altar linens.

In 1966, the new St. Mary's Catholic Church was opened at 1700 Missoula Ave.

Old St. Mary's served as the Community Action Center of the Rocky Mountain Development Council from about 1968-1977.

The building has been home to Calvary Chapel of Helena since about 1993.