Fresno is Spanish for "ash tree" is a city in Fresno County, California, U.S. county seat. It occupies roughly 112 square miles in the middle of the San Joaquin Valley, the southern part of Central Valley in California. Fresno was founded as a Central Pacific Railroad railway station in 1872, before being incorporated in 1885. Since then, the city has become an economic center for Fresno County and the San Joaquin Valley, with most of the surrounding areas in the Metropolitan Fresno region mostly tied to large-scale agricultural development. Fresno has a population of over 530,000 people.