State Route 38 is a mostly rural and scenic state highway in the U.S. state of California, connecting Interstate 10 in Redlands with State Route 18 in the Big Bear Lake area. It is one of the primary routes into the San Bernardino Mountains. Despite the orientation of its alignment, SR 38 is assigned in a west–east direction.

Interstate 10 (I-10) is a transcontinental Interstate Highway in the United States, stretching from Santa Monica, California, to Jacksonville, Florida. The segment of I-10 in California, also known as the Pearl Harbor Memorial Highway, runs east from Santa Monica through Los Angeles, San Bernardino, and Palm Springs before crossing into the state of Arizona. In the Greater Los Angeles area, it is known as the Santa Monica and San Bernardino freeways, linked by a short concurrency on I-5 at the East Los Angeles Interchange. I-10 also has parts designated as the Rosa Parks and Sonny Bono Memorial freeways. Some parts were also formerly designated as the Christopher Columbus Transcontinental Highway. However, the California State Legislature removed this designation following the passage of a bill on August 31, 2022. I-10 is also known colloquially as "the 10" to Southern California residents (See also California English § Freeways).