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 long, with a maximum width of , and a total area of . Together with Mill Rock, Roosevelt Island constitutes Manhattan's Census Tract 238, which has a land area of , and had a population of 9,520, as of the 2000 United States Census. The Roosevelt Island Operating Corporation estimated its population was about 12,000 in 2007.