Carter Lake is a city in Pottawattamie County, Iowa, United States, and a suburb of Omaha, Nebraska, and sits surrounding the south and west sides of the region's major airport, Eppley Airfield. The population was 3,785 at the 2010 census.
Carter Lake is an example of the border irregularities of the United States, being the only city in Iowa located west of the Missouri River. In March 1877, a flood redirected the course of the river 1.25 mi (2 km) to the southeast. The remnants of the old river course, called Saratoga Bend, became an oxbow lake, named Carter Lake. Soon after the formation of the lake, the site became a flourishing recreational area. It included "a boathouse at the foot of Locust street, hotels and club houses were numerous and the lake was the scene of many a pleasant rowing and fishing party."
In 1892, after extensive litigation between Iowa and Nebraska, the Supreme Court of the United States ruled that Carter Lake belonged to Iowa in Nebraska v. Iowa, 143 U.S. 359 (1892). Although the general rule is that state boundaries follow gradual changes in the course of a river, the Court ruled that an exception exists when a river avulses one of its bends. In 1972, the Supreme Court made another ruling on the circumstances of Carter Lake when it ruled on a boundary dispute between the two states in Nebraska v.