Mission San Francisco Solano On July 4, 1823, Padre José Altimira founded this northernmost of California's Franciscan missions, the only one established 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 sold in 1881. This plaque replaces one originally dedicated by the Historic Landmark Committee, Native Sons of the Golden West, 1926. California Registered Historical Landmark No. 3