The mission of La Grande celebrated its first Mass in 1867 with Fr. Dielman, Pastor of Baker City. In 1880 the first resident priest, Fr. R. Hartlieb arrived. The first church was erected and dedicated on November 19, 1882 in Island City. In August of 1888 Fr. J.F. Broillard became pastor and in 1890 erected a church at the present site in La Grande. On July 17, 1892, the church was blessed under the title Immaculate Conception of the Blessed Virgin Mary, by Archbishop Gross of Oregon City.

In 1915 the cornerstone of the present church building was laid by Bishop O’Reilly on Oct. 25th. On January 20, 1916 Bishop O’Reilly dedicated the new church under the title the Immaculate Conception. The church is usually called “Our Lady of the Valley”.

On September 1, 1894 Sacred Heart Academy, a parochial school, was opened in La Grande. It served children in the La Grande area for 36 years before closing its doors in May of 1930. The Sacred Heart Academy building was destroyed by fire in January of 1932. In keeping with the Catholic school tradition Marian Academy opened its doors in September of 2008 and remained open until June of 2016.

Our Lady of the Valley church has 2 mission churches – Sacred Heart in Union and St. Mary’s in Elgin.