Casa Grande Site From the Sonoma State Historic Park Plan November, 1986. Used with permission.
Site of the Casa Grande, Vallejo’s first permanent house: After establishment of the garrison villa of Sonoma, Lieutenant Vallejo began construction of a house for himself, fronting the plaza that lies to the south of the site. The house, built partially of material salvaged from the ruined mission, was completed by 1836. From that year to 1852, the Casa Grande was the permanent home of Vallejo. It might also be said that before 1846, the home served as a military headquarters for the Mexican forces of California and the northern frontier district.
In the American period the Vallejos, on occasion, returned to the home, while remodeling was conducted on their new residence (after 1852) at Lachryma Montis. Here, also, Vallejo maintained an office, where in the 1860’s he worked on his history of California. The fire that destroyed the Casa Grande in 1867 destroyed the first draft of the history. Some time later, Vallejo was encouraged to start a new draft, and produced the five-volume manuscript that is now in the Bancroft Library at the University of California, Berkeley.
In addition to his private use, Vallejo leased rooms to other residents. At times (1849-1851), army officers assigned to the Post of Sonoma rented rooms. In 1854, Dr. John Van Mehr established his St. Mary’s Hall for Young Ladies in the Casa Grande. The school was so successful as a boarding school that Rev. Van Mehr, in 1855, expanded into an adjacent wing of the Casa Grande, which is know today as the Servants’ Quarters.
The late summer of 1856 witnessed the beginning of a diphtheria epidemic that raged into the fall of that year; four of Van Mehr’s children died. He sent their bodies to San Francisco and apparently in December closed the school in Sonoma and transferred his residence to San Francisco.
As noted earlier, the Casa Grand burned in February in 1867, and the debris was apparently either allowed to crumble about the current buildings or was removed, possibly to the area known as the “Spain Street Dump.” The western edge of this structural site is not on state park property. Archeological work during the past 20 years has revealed that much of the foundation still exists.
Servants’ Quarters or dormitory: Mentioned above as housing part of Van Mehr’s school, the existing remnant of the Casa Grande, an adobe two-story wing running north and south and measuring 18 feet wide by 109 feet long, once intersected the Casa Grande at its western end. Identified in 1849 “as a dormitory for the Indians on the premises, of whom there were a great number, and a kitchen”, it survived the fire of 1867. Originally, it probably had four barracks-like rooms on each floor. On the upper floor, there is the addition of a squared chamber at either end. Following the fire that destroyed the Casa Grande, the structure saw use as a tenement, and, on the ground floor, as a wine cellar.
Tower site: At the extreme southwest corner of the Casa Grande site, there exists the site of a sentinel tower built of adobe, three stories high, with an upper balcony, dating to the original house construction. This tower was no doubt part of the defense system of early frontier Sonoma during the Vallejo years. It apparently fell into ruin in the 1850s, and was gone by the early 1860s. This site is not on state park property.
In addition to the Casa Grande complex, there were a number of small outbuildings constructed by the Vallejo labor force. These small adobe structures have all disappeared as changes or improvements were made to the grounds during the American period (see Toscano Hotel and Annexes). The area including the current parking facilities for the unit was historically a vineyard and house garden for the Vallejos.
In 1957, the Casa Grande site, the Servants’ Quarters, and the Toscano Hotel complex were purchased by the state from Amelia Walton.