The purpose of the park is to preserve and protect a substantial area on the western slope of the central Coast Range inland from Aņo Nuevo Point. The property contains a diversity of plant communities, including old growth forest freshwater marsh, red alder riparian forest and knobcone pine forest. Its four perennial streams support steelhead trout and coho salmon, and its wetlands are habitat to the rare San Francisco garter snake and red-legged frog. There is a major Northern Elephant Seal colony on Aņo Nuevo Point, and the seals commonly haul out on beaches within the park, where they are easily seen from observation points. Cultural resources include the remnants of a prehistoric Native American village site and a number of structures from the nineteenth century Cascade Ranch. In conjunction with adjacent and nearby public lands, the unit permits the protection of important regional ecological corridors.