DeSoto National Wildlife Refuge is part of a network of refuges devoted to preserving and restoring increasingly scarce habitat for migratory waterfowl and other wildlife. The refuge is comprised of 8,358 acres in Iowa and Nebraska and lies in the Missouri River Valley floodplain on a former meander of the Missouri River. Each year, especially during the fall, spectacular flights of ducks and geese mark the changing seasons along this traditional waterfowl flyway. An interesting assortment of warblers, raptors, shorebirds, and other bird life can be observed also. The 1968 excavation of the steamboat Bertrand, which sank in 1865, adds a major historical emphasis to the refuge program. The 200,000 pieces in the Bertrand Collection provide one of the most significant assemblages of Civil War era artifacts in the country. A former oxbow of the Missouri River, DeSoto Lake, provides recreational use for up to 250,000 visitors annually. The DeSoto Visitor Center provides an introduction to the refuge, exhibits the Bertrand Collection, and contains interpretive displays on the historical development of the Missouri River Basin, the ecological impacts of that development, and the natural history of the area.