Rancho San Julian was established in 1817 as a source for meat, tallow, leather, and horses for the King of Spain's soldiers at the Presidio of Santa Barbara, California. Presidio Comandante Don Jose Antonio de la Guerra y Noriega received Rancho San Julian, about 48,000 acres, in lieu of back pay. The Rancho passed to Don Jose's sons, who sold it to Gaspar Orena during the difficult financial times caused by the drought of 1862-1864.

Albert and Thomas Dibblee purchase Rancho San Julian in 1867. A year later, Thomas Bloodgood Dibblee married Francisca de la Guerra, granddaughter of Don Jose, keeping the Rancho in the de la Guerra family.

In 1875, the Dibblees along with W. W. and Hubbard Hollister, built a pier at Gaviota for shipping cattle and sheep to the San Francisco market. Later, in the 1890s when the railroad reached Guadalupe, they drove the stock to the rail terminal there.

When Albert and Thomas Dibblee both died in 1895, Albert's family received the Jalama (western) portion of the land and Thomas's descendants retained San Julian. In 2000, 15,000 acres remained of the original 25,000 left at the time of the 1895 subdivision. As of 2020, Rancho San Julian continues to be held and worked by the descendents of Thomas Bloodgood Dibblee.