The Pomona Valley's story began between 2000 and 500 B.C.E. with the inhabitance of the Gabrielino (Tongva) and Serrano Natives, nomadic hunter-gatherers who often lived near sources of water.
This changed in the late 1700s with the beginning of Spanish interest in the land now known as California and their introduction of the mission system in 1769. The San Gabriel Mission was built in Southern California in 1771 as the fourth of twenty-one missions, by 1800 holding a population of more than 1,000 natives. It was the most productive mission within the system because of its fertile land, but like the others, it had an overall negative impact on the native population.
In 1821, Mexico declared independence from Spain and gained control of California in the process. Thirteen years later, Mexico passed the Secularization Act of 1834, opening mission lands to private ownership and thus setting the stage for Pomona Valley’s new residents.