which in turn appears to have first been named in 1854 after the old Rancho Las Salinas land grant, parts of which included the city. River course Headwaters The river begins in southern San Luis Obispo County, approximately east of the summit point of Pine Ridge, at a point just off of Agua Escondido Road, coming down off of the slopes of the Los Machos Hills of the Los Padres National Forest. The only dam situated directly on the Salinas River (the Salinas Dam) forms the small Santa Margarita Reservoir. Upriver The Salinas flows down the valley bounded on its southwestern side by the Santa Lucia Mountain Range, and bounded on its northeastern side by the Gabilan Mountain Range. It flows past Atascadero and Paso Robles (to Monterey). It receives the natural outflow of the Estrella River and the controlled outflows of the Nacimiento and San Antonio reservoirs through their respective river tributaries in southern Monterey County. The river passes through the active San Ardo Oil Field, and then into and through the Salinas Valley. It flows past many small towns in the valley, including King City, Greenfield, and Soledad, where it combines with the flash-flood prone Arroyo Seco, its fourth major tributary (in wet years). Outflow It flows south of the city of Salinas before cutting through Fort Ord and flows into central Monterey Bay approximately 3 miles west of Castroville. The final stretch of the river forms a lagoon protected by the Salinas River National Wildlife Refuge and its outflow to Monterey Bay is blocked by sand dunes except during winter high-water flows. Pre-1906 course The land owners altered the course of the river by filling in the river bed during the dry season. This allowed them to farm all of their land and use the water as they saw fit. The old stream bed went from the Old Salinas River, joining Elkhorn Slough on Monterey Bay near Moss Landing, to the present course where the main channel's mouth is directly on the Pacific Ocean. The old Salinas River channel that diverts north behind the sand dunes along the ocean, acts as an overflow channel during the rainy season. River Road Commencing from Hill Town running south along the western banks of the Salinas River to Gonzales is River Road. This road also falls along the edge of the Santa Lucia Highlands AVA, giving rise to its designation