Santa Maria River on the Central Coast of California, is formed at the confluence of the Sisquoc River and Cuyama River, just east of the city of Santa Maria, and flows 24.4 miles (39.3 km) to its delta at the Pacific Ocean. The entire river defines the border between northern Santa Barbara County and southern San Luis Obispo County, up to the Sisquoc River, with a major bridge on Highway 101 passing over it. The Santa Maria River Fault is a tectonic fault that roughly corresponds with the course of the river.