State Route 186, also known as Algodones Road, is a state highway in the U.S. state of California that connects Interstate 8 (I-8) in Imperial County with the U.S.–Mexico border near the Colorado River. Its southern terminus is at the Andrade Port of Entry, which connects it to Los Algodones, Baja California, and its northern terminus is near Winterhaven, California in the location of Araz Junction. The route is only 2.070 miles (3.331 km) long, heading along the length of the Alamo Canal and the All-American Canal within the boundaries of the Fort Yuma-Quechan Reservation. The route was assigned in 1972 in Imperial County, and the interchange with I-8 was constructed a year later.

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.