The University of California, Riverside (UCR or UC Riverside) is a public land-grant research university in Riverside, California, United States. It is one of the ten campuses of the University of California system. The main campus sits on 1,900 acres (769 ha) in a suburban district of Riverside with a branch campus of 20 acres (8 ha) in Palm Desert. In 1907, the predecessor to UCR was founded as the UC Citrus Experiment Station, which conducted research in biological pest control and the use of growth regulators. UCR's undergraduate College of Letters and Science opened in 1954. The Regents of the University of California declared UCR a general campus of the system in 1959, and graduate students were admitted in 1961.