State Route 83 (SR 83), also or primarily known as Euclid Avenue, is a state highway and city street in the U.S. state of California. Officially, SR 83 runs from the Chino Valley Freeway (State Route 71) in Chino Hills north to the San Bernardino Freeway (Interstate 10) in Upland. Euclid Avenue then continues north through Upland to the unincorporated community of San Antonio Heights. Euclid Avenue passes through several historic districts. A segment of the road is listed on the National Register of Historic Places.