The Adirondack Park is a publicly protected area in northeast New York. It is the largest park and the largest state-level protected area in the contiguous United States, and the largest National Historic Landmark..The park covers some 6.1 million acres (9,400 mi&Atilde;/24,700 km&Atilde;), a land area greater than Vermont, or than Yellowstone, Yosemite, Grand Canyon, Glacier, and Great Smoky Mountains National Parks combined.