Le Grand Champ Bottom

Le Grand Champ (French for "the big field") is an alluvial floodplain, also called a bottom, extending along the Mississippi River in Ste. Genevieve County, Missouri.

The American Bottom stretches from St. Louis south along the east side of the Mississippi River all the way to the mouth of the Kaskaskia River, just north of Fort Kaskaskia, Illinois. At Morrow Island the American Bottom is broken by the Mississippi River, and on the west side of the Mississippi River the alluvial plain continues as the "Le Grand Champ" or Big Field Bottom, which includes Kaskaskia Island.