Jackson Hole refers to the valley that begins six miles south of Yellowstone National Park and stretches for about 80 miles along the Snake River. Jackson is the main town in the valley. US 191, commonly called the John D. Rockefeller Jr. Pkwy, runs through Jackson Hole to the south entrance of Yellowstone National Park. However, US Highway 191 is closed seasonally due to winter weather. The road closure can stretch from early November until mid-May.