SR 142 begins in the city of
Brea as Valencia Avenue at a junction with
SR 90. The road heads northeast to an intersection with Carbon Canyon Road, which assumes the designation of SR 142 and continues east through
Carbon Canyon Regional Park. SR 142 continues into the community of
Olinda before crossing into the
Sleepy Hollow area of the city of
Chino Hills in
San Bernardino County. SR 142 continues northeast through Chino Hills to an intersection, where it continues eastbound on Chino Hills Parkway. The highway ends at an interchange with
SR 71 on the border of Chino Hills and
Chino, near the
California Institution for Men, a
state prison. SR 142 is part of the
California Freeway and Expressway System, and is part of the
National Highway System, a network of highways that are considered essential to the country's economy, defense, and mobility by the
Federal Highway Administration. SR 142 is eligible to be included in the
State Scenic Highway System, but it is not officially designated as a scenic highway by the
California Department of Transportation. ==History==