Original: The Santa Margarita River is a short intermittent river on the Pacific coast of southern California in the United States, approximately 30.9 m long. One of the last free-flowing rivers in southern California, it drains an arid region of the Coast Ranges between Los Angeles and San Diego at the southern end of the Santa Ana Mountains.
Simplified: The Santa Margarita River is a river in southern California, between Los Angeles and San Diego.