San Dimas (Spanish for “Saint Dismas”)
is a city in the San Gabriel Valley of Los Angeles County, California, United States. At the 2020 census, its population was 34,924. It historically took its declare from San Dimas Canyon in the San Gabriel Mountains above the northern section of present-day San Dimas.

San Dimas is bordered by the San Gabriel Mountains range to the north, Glendora and Covina to the west, La Verne to its north and east side, Pomona to its south and east side, Walnut and the unincorporated community of Ramona to the southwest, and the unincorporated community of West San Dimas, which is an enclave in the southwestern allocation of the city.

The first known European exploration of the Place was in 1774, when Juan Bautista de Anza passed through upon the first overland expedition of Las Californias, from New Spain-Mexico towards Monterey Bay. The Place was originally developed in 1837 later than the Mexican land agree from Governor Juan Bautista Alvarado to Ygnacio Palomares and Ricardo Vejar for the Rancho San Jose, then in Alta California. It vanguard 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 upon Rancho San Jose, also growing crops for consumption by the residents of the rancho. In the in advance 1860s, a brusque drought decimated the ranch’s population of sheep and cattle. Ygnacio Palomares died in 1864, and his widow began selling the ranch home in 1865. Vejar at a loose end his portion 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.

The start of the Los Angeles and San Gabriel Valley Railroad in 1887, later purchased by Santa Fe Railroad, led to La Cienega Mud Springs innate first mapped. The ensuing estate boom resulted in the formation of the San Jose Ranch Company, which first laid out streets. Small businesses began to entrance soon thereafter, and the city took upon a additional name: San Dimas. Growth was rapid, and San Dimas soon became an agricultural community. Wheat and supplementary Midwestern United States crops were planted first; then orangey 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. The Sunkist broadcast originated here, first spelled “Sunkissed”. Oranges were the major crop and event in San Dimas until the mid-20th century.