In the 1830’s, the territory of Iowa held an attraction for German settlers. Many came to join relatives near Guttenberg, but found that they would fare better by crossing the Mississippi and settling east of the river near Glen Haven. Father William  Verhoeff, C.S.C., an immigrant priest from Holland (a Crosier Father), had settled in the Potosi area in 1861 to minister to the spiritual needs of those in the vast Mississippi River area. He encouraged the people of Glen Haven to provide a suitable place for the Sacrifice of the Mass.  Hence in 1864, the Mission of Glen Haven composed of about 52 German families was established by Bishop Henni of the Milwaukee Diocese. It was attended on Saturday and Sunday by Rev. Verhoeff, who remained the pastor at St. Thomas Parish of Potosi, until 1867. Mass was first offered in the German schoolhouse on the property of Joseph Rauch. Later, mass was moved into Glen Haven to the hotel owned by John Mock.
      The mission built their first church, “The Old Rock Church” in 1866. The stone masons were Peter and Joseph Rauch, who directed members of the parish in the construction. This structure still stands in Glen Haven. In 1867, the parish became a mission of Cassville and remained so for over 30 years. Cassville’s pastor, Rev. J. A. Moes, 1867-1868; celebrated mass once a month in the Rock Church, which became known as “Glen Haven Sunday”.  Other Cassville mission pastors were: Rev. Joseph Albers, 1868-1871; Rev. Maximillian DeBecke, 1871-1873; Rev. Charles Schraudenbock, 1873-1876; Rev. J. Gmeiner, 1876-1878; Rev. M. J. Meurer, 1878-1880; Rev. J. Decker, 1880; Rev. August Gardhaus, 1881-1882; Rev. J. Dreis, 1882; Rev. Leopold Drexel, 1882-1888; Rev A. M. Rossbach, 1888-1897; and Rev. Francis Pischery, 1897-1899.  In 1892 under Rev. Rossbach, the parish was incorporated.

In 1899, the parish was made a mission of Bloomington and was served by their pastor, Rev. Nicholas Hanert. By 1901, the Rock Church couldn’t accommodate a growing congregation.  Under the direction of Rev. Hanert, 1899-1904; the parish raised the funds to build the current church at the cost of $8,611.07. Gothic in style, the church had a seating capacity of 275. The statue of the Blessed Virgin holding the Infant Jesus was transferred to the new high altar and remains today. The first mass was held in the new structure on November 21, 1903 and the church was dedicated on May 31,1904.  In 1905, the parish became a member of the LaCrosse Diocese, which was formed when the Milwaukee Diocese was divided. A rectory was built in 1911, when the parish received its first resident pastor, Rev. Bernard Weyer, 1911-1916. Rev. P. Becker was the next pastor from 1916-1917.

  The cornerstone for a parochial school was laid in 1918 under the pastorate of Rev. Edmund A. Beyer, 1918-1925.  In September of 1919, St. Mary’s Catholic School opened with an enrollment of 73 pupils under the care of five Notre Dame Sisters.  In 1921, the school added 9^th and 10^th grades to provide a high school for the local students.  These grade levels were discontinued two years later due to increased enrollment in the grade school. Other resident pastors included:  Rev. Peter A. Beschta, 1926-1930; Rev. E. A. Beyer, 1930-1932; Rev. Peter Trierweiler, 1932-1944; Rev. Fred Karlheim, 1944-1945; and Rev. Lawrence J. Bindl, 1945-1947. In 1946, during Father Bindl’s service, the Madison Diocese was formed and St. Mary’s became part of it. The Rev. John Eberhardy served from 1947-1953; Rev. Paul M. Dwyer, 1953-1954; Rev. Ralph Ott, 1954-1958; Rev. Lambert M. Marx, 1958-1962; and Rev. George Grotkin, 1962-1964.

         In 1964, under the pastorate of Rev. Francis J. Dominic, 1964-1970; the parish celebrated its Centennial with a roster of 129 families. Then, Rev. Raymond I. Haas was the pastor from 1970-1974. Rev. John Gebhard became the pastor from 1974-1982.  A talented woodworker, he added character to the side and main altars of the church and remodeled the rectory. The grade school closed in 1974 with students enrolling in Bloomington and Cassville School Districts. 
     The last resident priest, Rev. Richard Jiru served from 1982-1991. Under his direction, the church was redecorated and painted in 1982, and the school was raised in 1983. The parish was again made a mission of St. Charles’ Parish in Cassville in June of 1985. Father Jiru relocated to St. Charles Rectory. No longer needed, the rectory was sold at public auction in November of that year.  The parish celebrated its 125^th Anniversary in 1989 with a membership of 101 families. Rev. John (Bud) Satterlee was the next Cassville Mission Pastor from 1991-1995. Then, Rev. John Norder served from 1995-2010.

         In 2010, under a directive from Bishop Donald J. Hying and the Diocese of Madison, a cluster was formed from parishes in four local communities.  Holy Mary Help of Christians Parish, Glen Haven; St. Charles Borromeo Parish, Cassville; St. John’s Parish, Patch Grove; and St. Mary’s Parish, Bloomington were all served by the new pastor, Rev. John Meinholz, from 2010-2022; who resided in Bloomington. 
      On June 21, 2014, a “150^th Sesquicentennial Celebration” was held for the 66 family/single member parish. The day included a pork roast, games, a raffle, mass and a fireworks display at dusk. In the first few months of 2017, the church interior was restored and painted by the John C. Kaiser Company from Dubuque, IA at a cost of $69,855.  In 2020, with the Covid epidemic, it was changed to an annual “Drive Through Pork Chop Dinner” event. Father Meinholz retired from the priesthood in July of 2022.

Rev. Gregory Ihm was then appointed the pastor of the cluster for one year: July, 2022 to June, 2023. During Father Ihm’s tenure, the “Into the Deep” initiative had begun. This resulted in the regrouping of parishes into 30 pastorates in the Diocese of Madison. In July of 2023, a group of 7 parishes, referred to as Pastorate #1, from Glen Haven, Bloomington, Cassville, Patch Grove, Lancaster and Potosi were merged and served by three priests:  Rev. Stephen Brunner, Rev. Mark Miller and Rev. Sudhakar Reddy Devarapu.  In August and September of 2023, Krause Konstruction from Coon Valley, WI repaired and put a new roof on the church steeple. This $69,320 expense was covered by a generous donation from the Ray/Kay Eckstein Foundation.