From the plaque:
This was the site of Rancho
los Guilucos (18,833 acres), granted in 1839 by Governor Juan Bautista
Alvarado to John Wilson and his wife, Ramona Carrillo,
sister-in-law of General Mariano Guadalupe Vallejo. The house, constructed in 1858 by William Hood for
his bride, Elisa Shaw of Sonoma, incorporates the original
bricks fired on the property, and has been in continuous use. The property was purchased
in 1943 by the California Department of the Youth Authority
for Los Guilucos School for Girls.
Plaque placed by the California State Park Commission in cooperation with Los Guilucos Citizens Advisory Committee and the Sonoma Valley Historical Society, May 28, 1960.