Criterion (ix): Redwood National and State Parks preserve the largest remaining contiguous ancient coast redwood forest in the world in their original forest and streamside settings. IntegrityThe 16,442 hectares of old growth redwood forest in Redwood National and State Parks preserves some of the largest remaining contiguous ancient coast redwood forest in the world. As of 2018, the size of Redwood National and State Parks is 54,168 hectares and the total area of old growth redwood forests is 16,442 hectares. Redwood National Park is managed under the authority of the National Park Service Organic Act which established the United States National Park Service. In addition, both the National Park Service and California State Parks have established Management Policies which provide broader direction for all National Park Service units and California State Park units, including Redwood National and State Parks.