From the plaque:
In August 1863, Archbishop
Joseph Sadoc Alemany, O.P. opened St. Mary's College at this location
with a faculty of two diocesan priests, four laymen, and
two student teachers. In August 1868, at the invitation
of the archbishop, Brother Justin McMahon and seven Christian
Brothers took charge of St. Mary's. The Christian brothers have manifested the principle characterized by the best educational institutions, excellence.
Plaque placed by the California State Park Commission in cooperation with St. Mary's College, its alumni, and the California Historical Society, September 29, 1962.