Interstate 8 (
I-8) is an
Interstate Highway in the southwestern United States. It runs from the southern edge of
Mission Bay at Sunset Cliffs Boulevard, in
San Diego, California, almost at the Pacific Ocean, to the junction with
I-10, just southeast of
Casa Grande, Arizona. In California, the freeway travels through the San Diego metropolitan area as the
Ocean Beach Freeway and the
Mission Valley Freeway before traversing the
Cuyamaca Mountains and providing access through the
Imperial Valley, including the city of
El Centro. Crossing the
Colorado River into
Arizona, I-8 continues through the city of
Yuma across the
Sonoran Desert to Casa Grande, in between the cities of
Phoenix and
Tucson.