The San Dieguito River is a river located in southern California, primarily flowing through San Diego County. It originates in the Cuyamaca Mountains and travels approximately 55 miles before emptying into the Pacific Ocean near Del Mar. The river's watershed covers a diverse range of ecosystems, including forests, grasslands, and wetlands. The river is an important resource for local wildlife and serves as a recreational area for residents and visitors. It is also part of the San Dieguito River Park, which aims to preserve the natural environment and provide opportunities for hiking, biking, and birdwatching along its trails.