Omaha is the largest city in the state of Nebraska, United States, and is the county seat of Douglas County. It is located in the Midwestern United States on the Missouri River, about 20 miles (30 km) north of the mouth of the Platte River. Omaha is the anchor of the Omaha-Council Bluffs metropolitan area, with Council Bluffs, Iowa sitting adjacent to Omaha across the Missouri River. According to the 2008 estimate by the United States Census Bureau, Omaha's population was 432,921. The city is the nation's 42nd-largest, according to 2007 U.S. Census Bureau estimates; along with its suburbs Omaha formed the 60th-largest metropolitan area in the United States in 2000, with an estimated population of 829,890 residing in eight counties. There are more than 1.2 million residents within a 50 mile (80 km) radius of the city's center.