Running from the equivalent of East 46th to 85th Streets on Manhattan Island, it is about 2 miles (3.2 km) long, with a maximum width of 800 feet (240 m), and a total area of 147 acres (0.59 km2). Together with Mill Rock, Roosevelt Island constitutes Manhattan's Census Tract 238, which has a land area of 0.279 sq mi (0.72 km2),[3] and had a population of 9,520 as of the 2000 United States Census.[4][note 1] It had a population of 11,661 as of the 2010 United States Census.[1]