Grand Teton National Park is a national park of the United States in northwestern Wyoming. At approximately 310,000 acres (1,300 km²), the park includes the major peaks of the 40-mile-long (64 km) Teton Range as well as most of the northern sections of the valley known as Jackson Hole. Grand Teton National Park is 10 miles (16 km) south of Yellowstone National Park, to which it is connected by the John D. Rockefeller Jr. Memorial Parkway which is managed by the National Park Service. Along with surrounding national forests, these three protected areas constitute the almost 22-million-acre (89,000-square-kilometer) Greater Yellowstone Ecosystem, one of the world's largest intact mid-latitude temperate ecosystems.