The Indian population at the Santa Barbara Mission peaked in 1803 at 1,792. Due to the introduction of European diseases the death rate began to exceed the birth rate among neophytes (at almost all the missions). By 1828 all of the indigenous Chumash villages in the Santa Barbara ceased to exist. The population of the mission gradually declined. It was 628 in 1832, the last year for which we have annual reports that summarized each mission's spiritual and material status.
The mission was secularized in 1834. A Lay administrator was appointed to oversee temporal affairs. The neophyte population gradually melted away. Some Indians accepted positions at the "ranchos" and became vaqueros or field hands. Others blended into the local population. Some families continued to live on the former mission grounds. In 1845 much of the mission was leased to Nicholas Den and Daniel Hill. The mission church continued to function and the mission was never totally abandoned.