The Redwood National and State Parks (RNSP) are a complex of one United States national park and three California state parks located along the coast of northern California. The combined RNSP contain Redwood National Park, Del Norte Coast Redwoods State Park, Jedediah Smith Redwoods State Park, and Prairie Creek Redwoods State Park. The parks' 139,000 acres (560 km) preserve 45 percent of all remaining old-growth coast redwood forests.
Located in Del Norte and Humboldt counties, the four parks protect the endangered coast redwood (Sequoia sempervirens)—the tallest, among the oldest, and one of the most massive tree species on Earth—which thrives in the humid temperate rainforest. The park region is highly seismically active and prone to tsunamis. The parks preserve 37 miles (60 km) of pristine coastline, indigenous flora, fauna, grassland prairie, cultural resources, waterways, as well as threatened animal species, such as the Chinook salmon, northern spotted owl, and Steller's sea lion.