The Fresno River (Spanish for "ash tree") is a river in Central California and a major tributary of the San Joaquin River. It runs approximately 83 miles (134 km) from the Sierra Nevada Range to the San Joaquin River if measured from the source of Rainier Creek, near Raymond Mountain in Yosemite National Park. Although called the 'Fresno' River, it is one of the largest and longest river systems in Madera County.