About San Dimas

San Dimas is a city located in the San Gabriel Valley, in Los Angeles County, California. As of the 2010 census, the city had a total population of 33,371. The city historically took its name from San Dimas Canyon in the San Gabriel Mountains above the northern section of present day San Dimas. San Dimas is named in Spanish after Saint Dismas, the repentant and crucified thief.

The Tongva Native Americans lived in the area, and along with other tribes, in the region for over 8,000 years. These earliest residents, also referred to as the Tongva-Gabrieliño Tribe, of what is now known as San Dimas became part of the Mission Indians after Spanish colonization from the Mission San Gabriel occupied their lands in the late 18th century.

The first known European exploration of the area was in 1774, when Juan Bautista De Anza passed through on the first overland expedition of Las Californias, fromNew Spain-Mexico towards Monterey Bay. The area was originally developed in 1837 with the Mexican land grant from Governor Juan Bautista Alvarado toYgnacio Palomares and Ricardo Vejar for the Rancho San Jose, then in Alta California. It later became known as La Cienega Mud Springs, so named because of local mud springs that created a riparian marsh and healing place. Palomares and Vejar conducted sheep and cattle operations on Rancho San Jose, also growing crops for consumption by the residents of the rancho. In the early 1860s, a severe drought decimated the ranch's population of sheep and cattle. Ygnacio Palomares died in 1864, and his widow began selling the ranch land in 1865. Vejar lost his share by foreclosure to two Los Angeles merchants, Isaac Schlesinger and Hyman Tischler, in 1864. In 1866, Schlesinger and Tischler sold the ranch to Louis Phillips.

It was the arrival of the Santa Fe Railroad in 1887 that La Cienega Mud Springs was first mapped. The resulting land boom resulted in the formation of the San Jose Ranch Company, which first laid out streets. Small businesses began to open soon thereafter, and the city took on a new name: San Dimas. Growth was rapid, and San Dimas soon became an agricultural community, wheat and other Midwestern United States crops were planted first, then orange and lemon groves covered the town and the San Gabriel Valley. At one time, four citrus packing houses and a marmalade factory were located in San Dimas.