Roosevelt Island is a narrow island in New York City's East River. It lies between Manhattan Island to its west and the borough of Queens on Long Island to its east, and is part of the borough of Manhattan. 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). and had a population of 9,520 in 2000 according to the US Census.