Grand Teton National Park is an American national park in northwestern Wyoming. At approximately 310,000 acres (1,300 km
2), 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 only 10 miles (16 km) south of Yellowstone National Park, to which it is connected by the National Park Service–managed John D. Rockefeller Jr. Memorial Parkway. Along with surrounding national forests, these three protected areas constitute the almost 18-million-acre (73,000-square-kilometer) Greater Yellowstone Ecosystem, one of the world's largest intact mid-latitude temperate ecosystems.