More than one hundred fifty years ago, in 1837, Dona Maria Ignacio Lopez de Carrillo made the arduous trip from Sand Diego to Sonoma to the home of her son-in-law, Mariano Vallejo. The senora then supervised the building of an adobe on two square leagues (8,800 acres) along Santa Rosa Creek on the site of a former Southern Pomo Indian village and possibly an assistencia mission that had been abandoned a few years earlier.
In 1841, Governor Manuel Jimeno confirmed the grant of the Rancho Cabeza de Santa Rosa. The Carrillo family continued ranching operations, raising 3000 head of cattle for hides and tallow, and hundreds of horses , as well as cultivating several hundred acres of grains, fruits, and vegetables.
Soon after the American conquest of California in the 1846-48 war, Dona Maria died and was buried beneath the chapel in Sonoma as she wished. The rancho was divided among her children, and the Carrillo adobe went to her daughter Juana, who had married David Mallagh.
In the early 1850's the adobe housed a store, an inn, and a post office, before losing its centrality as the newly founded town of Santa Rosa was a established a mile and half down the creek. Between 1860 and 1950 the building served many functions on the farm owned by the family of Feodor Hahman an early settler from Germany. In 1944 the 142 foot east-west wing of the adobe collapsed and disappeared, leaving only a "footprint" of its foundation rocks. Six years later the remainder of the building and surrounding seventeen acres became the property of the Roman Catholic Diocese of San Francisco.
In 1960 the newly established Diocese of Santa Rosa assumed control of the land. Since that time there have been several effort made to save the Carrillo Adobe, but despite modest successes, those past efforts have failed to arrest the buildings decay and resolve its future.
Now due to the efforts of the Friends of the Carrillo Adobe, public awareness has been increased. In 1988 the city's Cultural Heritage Board declared the Adobe a historical landmark, and with the continued cooperation of the Catholic Diocese, preservation of the Adobe is assured.