From the plaque:
On July 4, 1823, Padre José
Altamira founded this northernmost of California's Franciscan
missions, the only one established in California under
independent Mexico. In 1834, secularization orders were
carried out by Military Commandant Mariano G. Vallejo. San Francisco Solano became a parish church serving
the Pueblo and Sonoma Valley until it was sold in 1881. This plaque replaces one originally dedicated by the historic landmarks committee, Native Sons of the Golden West, 1926.
Plaque placed by the California State Park Commission in cooperation with the Sonoma Parlor No. III, Native Sons of the Golden West, July 14, 1963.