Fresno County was formed in 1856 from parts of Mariposa, Merced, and Tulare counties. Fresno is Spanish for “ash tree” and it was in recognition of the abundance of the shrubby local Ash, Fraxinus dipetala, growing along the San Joaquin River that it received its name. Parts of Fresno County’s territory were given to Mono County in 1861 and to Madera County in 1893.