Santa Maria River (California)

The Santa Maria River is a river in the Central Coast region of California, United States. Formed by the confluence of the Cuyama River and Sisquoc River near the city of Santa Maria, it flows westward for approximately 24 miles (39 km) to its mouth at the Pacific Ocean. The river marks the boundary between Santa Barbara County to the south and San Luis Obispo County to the north.

The Santa Maria River watershed encompasses a large area, including portions of the Coast Ranges and the Santa Maria Valley. It is characterized by a Mediterranean climate with dry summers and wet winters. The river's flow is highly variable, with significant fluctuations depending on seasonal rainfall.

The river is utilized for irrigation of the fertile agricultural lands of the Santa Maria Valley. The Twitchell Dam, located on the Cuyama River, provides flood control and water storage for irrigation.

The Santa Maria River Estuary, located at the river's mouth, is an ecologically significant area providing habitat for various species of birds, fish, and other wildlife. Conservation efforts are underway to protect and restore the estuary's natural resources.

Historically, the area surrounding the Santa Maria River was inhabited by the Chumash people. European settlement began in the late 18th century with the establishment of Spanish missions.