Washington has a variety of National Park Service units. Among these are the Alta Lake State Park, Lake Roosevelt National Recreation Area, San Juan Islands National Wildlife Refuge, as well as three national parks—the Olympic National Park, North Cascades National Park, and Mount Rainier National Park. The three national parks were established between 1899 and 1968. Almost 95 percent (876,517 acres, 354,714 hectares, 3,547.14 square kilometers) of Olympic National Park's area has been designated as wilderness under the National Wilderness Preservation System. Additionally, there are 143 state parks and9 national forests, run by the Washington State Park System and the United States Forest Service. The Okanogan National Forest is the largest national forest on the West Coast, encompassing . It is managed together as the Okanogan-Wenatchee National Forest, encompassing a considerably larger area of around .