This parish is distinct in having been
the first one in Montana Territory. There are older missions in Montana, the oldest being St Mary's Mission in Stephensville, ca 1840, but this was the first parish to be established in the territory. In the parish, the 1875 church and the 1911 church still stand, about 100 feet apart.
The first church was a log building 42' X 18' in size, with a 30' X 18' sanctuary, in which the first services were held on December 8, 1866, just over four months after Reverend DeRyckere's arrival in the town. At the time there were still fewer than 500 people in the town, mostly miners and their families.
The second church was built in 1871, a wood frame building located on the west side of Main Street. Shortly after, a more substantial and larger stone church was built on the east side of Clark Street, between Montana and St. Mary's Avenues. Begun in 1874, this church was blessed and housed the first services on March 19, 1875. It remains today as St Mary's Hall, beside the pastor's house. The Reverend had living quarters in the rear until 1893, when the pastor's residence was completed. In that year the rear of the church was turned into classrooms for a boys' school. Attendance never surpassed 20 students and by 1901 was down to 12 students. In that year the school was closed and the students thereafter attended public school.
The present Immaculate Conception Church was erected in 1911, the fourth catholic to be built in Deer Lodge. Primarily of brick, it is Gothic Revival in style, with a large square bell tower on the northwest corner and Gothic arched windows and openings throughout. Stained glass graces both sides of the sanctuary from end to end. The church remains in use today, thanks to a substantial congregation. Much larger than any of the previous buildings, it is probably a good indicator of the growth of Deer Lodge in the intervening years between 1875 and 1910, the year construction on the church began.
Most information herein is taken from the
Parish History.