The Adobe was designed to function both as a headquarters of a working ranch and as a defensive structure against attack by the Russians then living on the California coast or by the borderland's native tribes.

The wide, covered second-story veranda encased and protected the adobe walls from the weather and provided advantageous firing positions in case of an attack.

[7] The southwest section of the building contained the Vallejo family living area, for when they visited the ranch.

The outdoor kitchen and the dining room (featuring imported glass windows) were on the ground floor.

[9] In 1834, California Governor José Figueroa ordered Lieutenant (Teniente) Vallejo and his soldiers from the Presidio of San Francisco to move north of the Bay.

During 1836 Vallejo began construction of the ranch house, eventually investing an estimated $80,000 in labor and materials.

The rancho became one of the largest ranches north of the San Francisco Bay and a social-economic center of Northern California.

Products such as candles, soap, thousands of wool blankets, boots and shoes for military troops under Vallejo's command, and saddles were manufactured by native artisans in ranch shops.

The new grant extended the lands of Rancho Petaluma south down to the San Francisco Bay, and southeast past the present-day city of Vallejo.

There was a historic-era Indian ranchería along the east side of Adobe Creek where the other year-around workers lived in tule reed huts.

[14] Other unskilled Indians, who the Californios called gentiles, worked on a seasonal basis for the grain harvest, the cattle slaughter (la matanza) or things such as adobe brick making.

[15] The fate of the ranch turned in 1846–48 when the United States and Mexico went to war: Lieutenant Colonel Vallejo was imprisoned for his position in the Mexican military, and in his absence, John C. Frémont requisitioned and stripped the ranch of its horses, cattle and grain reserves for the California Battalion.

[17] In 1910, Native Sons of the Golden West, Petaluma Parlor #27 purchased what remained of General Mariano G. Vallejo's vast adobe ranch house.

[18] After years of work and fundraising, the fully restored historic site was turned over to the State of California in 1951.