Swan Lake National Wildlife Refuge was established by Executive Order 7563 on February 27, 1937. Purchase of 10,670 acres began at that time. Following purchase of land, the Civilian Conservation Corps began work on the refuge creating wetlands, constructing roads and buildings, and initiating the refuge farming program.

The primary purpose of the refuge is to provide nesting, resting, and feeding areas for waterfowl, primarily ducks. An important secondary purpose was to preserve a remnant flock of prairie chickens. Unfortunately, adequate grassland habitat to maintain a viable population of the birds was not available.

Since establishment of the refuge, the primary emphasis on waterfowl species has been expanded to include the Eastern Prairie Population of Canada geese. Canada geese were first observed using the refuge in the early 1940s, and numbers increased gradually to peak populations over 150,000 birds annually. Although these populations have steadily declined, Swan Lake is still considered a primary wintering area for Canada geese.

The refuge lies in the floodplain of the Grand River, near its confluence with the Missouri River in north-central Missouri. Flooding is common, especially during spring and summer periods. In addition to waterfowl management objectives, providing habitat for resident wildlife, protecting endangered and threatened species, encouraging biodiversity, developing shorebird habitat, and providing public opportunites for outdoor recreation and environmental education are on-going programs.

French fur traders, two of Daniel Boone's sons and a woodsman named Thomas Stanley explored Missouri before it became a State in 1821. They settled this country when it was a rich, untamed wilderness. Stanley lived off of the land and made his home in the hollow of a huge sycamore log not far from here. Deer, elk, bear, otter, wild turkey, and prairie chickens were found in abundance. In 1828, Thomas Stanley built a log trading post at the site of the present-day Sumner and thus pioneered a settlement trend which was later spurred by railway construction.

The human population grew and wildlife populations dwindled. In 1911, nearby Hog Lake was drained and converted to farmland. Drought and hard times hit in the nineteen thirties, and deer, elk, bear, otter and wild turkey became memories. Only a few flocks of prairie chickens remained.

Congress established Swan Lake National Wildlife Refuge in 1937 during the Depression years when the dust bowl conditions obscured the future of our Nation's migratory waterfowl. The Civilian Conservation Corps built roads and buildings and created wetlands. Farming to produce food for wildlife began.

The original refuge objective was to preserve habitat for ducks and prairie chickens. Canada geese had been rare visitors, stopping only briefly to rest on their long migration from their nesting grounds in northern Manitoba. Eight hundred geese wintered here for the first time in 1941. Their numbers increased in succeeding years and exceeded 100,000 every year through 1990. This refuge still has one of the largest concentrations of Canada geese in North America and is now the primary wintering area for the Eastern Prairie Population.

Swan Lake has converted to a modified biological farming program. Inorganic fertilizers are used to supplement annual legume plantings. About 1,000 are planted to corn, sorghum, clover, and wheat each year. All crops are left in the fields for geese and other wildlife. An additional 3,500 acres of low ground is managed to produce wild plants such as millet and smartweed which are used as food and cover by waterfowl. The remaining land is covered by forest, permanent grass, or native prairie.