The Crescenta Valley is a small inland valley in Los Angeles County, California, lying between the San Gabriel Mountains on the northeast and the Verdugo Mountains and San Rafael Hills on the southwest. It opens into the San Fernando Valley at the northwest and the San Gabriel Valley at the southeast. It is nearly bisected by the Verdugo Wash, a smaller valley separating the Verdugo Mountains from the San Rafael Hills. Most of the valley lies at an elevation of over 1,500 feet.

Los Angeles County, officially the County of Los Angeles, and sometimes abbreviated as L.A. County, is the most populous county in the United States, with 9,861,224 residents estimated in 2022. Its population is greater than that of 40 individual U.S. states. Comprising 88 incorporated cities and many unincorporated areas within a total area of 4,083 square miles (10,570 km2), it is home to more than a quarter of Californians and is one of the most ethnically diverse U.S. counties. The county's seat, Los Angeles, is the second most populous city in the United States and the most populous city in California, with 3,822,238 residents estimated in 2022. It is also known for being the home of the American film and television industry, a distinction it has held since the early 20th century which has given the county global prominence.