The Sixes River watershed drains approximately 134 square miles or 85,645 acres of land. Sixes River is situated almost entirely within Curry County except for a small area of the Upper Sixes Mainstem subwatershed that extends into Coos County. The Sixes is among the larger watersheds on the southern Oregon coast. Flowing in a westerly direction Sixes River crosses Highway 101 and drains into the Pacific Ocean just north of Cape Blanco. Elevations in the watershed range from sea level to approximately 3,315 feet. Major tributaries include the North Fork, Middle Fork, South Fork, Dry Creek, Edson Creek, and Crystal Creek. The upper portion of the basin is characterized by steeply sloped forested areas with narrow valleys and tributary streams that have moderately steep to very steep gradients. Grazing, rural residential development and other agricultural uses are dominant in the lower portion of the basin. Approximately 69% of the watershed is in private ownership.