Del Norte Coast Redwoods State Park is a state park of California, United States, and a component of the Redwood National and State Parks. The property is about half old-growth forest of coast redwoods and includes 8 miles of wild Pacific coastline. The park was significantly expanded in 2002 with the 25,000-acre Mill Creek Addition. Originally established in 1925, the park is now 31,261 acres. The park was designated part of the California Coast Ranges International Biosphere Reserve in 1983.