Socioeconomic benefits from economic growth and development have come at the expense of losses in ecological integrity and environmental quality. This kind of tradeoff is occurring in the Missouri River System (MRS). The MRS is operated by the U.S. Army Corps of Engineers (Corps) and consists of six mainstem dams and reservoirs located in Montana, North Dakota, South Dakota, and Nebraska (see Figure 5.1). While the MRS has benefited the basin to the tune of $1 billion annually (U.S. Army Corps of Engineers 1994), it has resulted in considerable environmental losses (see second section for details). In this regard, the National Research Council (2002) pointed out: “Degradation of the natural Missouri River ecosystem is clear and continuing. Large amounts of habitat have been transformed to enhance social benefits and the ecosystem has experienced a substantial reduction in biological productivity as a result. Natural riverine processes that are critical to providing ecological goods and services have been greatly altered. The ecosystem has been simplified and its production of goods and services greatly compromised.”