The Mississippi River presently forms Missouri's eastern border, but many millennia ago it ran through what is now southeastern Missouri, passing between the Ozark Plateau on the west and a narrow upland known as Crowley's Ridge. Geological evidence indicates that, about 18,000 years ago, the river ate through the ridge, shifted its course farther east and left in its former path an old channel that became home to a dense swamp. That area is now known as the Mingo Basin.
In the late 19th and early 20th centuries, the basin's virgin forests of cypress and tupelo trees were harvested. Efforts subsequently began to drain the land so it could be put to agricultural uses. When drainage of the basin's swamps proved difficult, they were used as open rangelands where cattle and swine roamed freely and trees were cleared to maintain pasturage. By the middle of the 20th century, the Mingo Basin had lost much of its natural cover and drainage activities had altered its natural water patterns.
In 1945, efforts to conserve the swamp led to the purchase of 21,676 acres to establish the Mingo National Wildlife Refuge. The state of Missouri began acquiring land in 1950 to create what is now the 6,234-acre Duck Creek Conservation Area, which borders the federal refuge. The basin's restored wetlands have hosted nesting bald eagles since 1985 and draw significant numbers of migrating and wintering waterfowl, including an estimated 125,000 mallards and 75,000 Canada geese within the refuge alone.
The Mingo Basin has been designated a priority conservation site by The Nature Conservancy. The Conservancy will continue to support the efforts of the U.S. Fish and Wildlife Service, Missouri Department of Conservation and other governmental partners, and non-profit organizations such as Ducks Unlimited and Mingo Swamp Friends, Inc., to restore the basin's bottomland hardwood forest, wetland and aquatic habitats and the natural communities those habitats shelter.
Specific strategies will include restoring, where feasible, the basin's natural water flows; controlling erosion and, thereby, reducing sedimentation that fills the basin's streams and wetlands; and controlling non-native species, such as reed canary grass.
More than 95 species of migratory waterfowl, the peregrine falcon and the endangered whooping crane are among the more than 250 bird species that have been recorded in the Mingo Basin. In addition, the basin's diverse habitats are known to shelter more than 38 species of mammals, 23 species of amphibians and 37 species of reptiles, including the western mud snake, a species of concern in Missouri.