The Mississippi Headwaters watershed is a 7,608 square mile area in north-central Minnesota which includes all land drained by the Mississippi River above the Crow Wing River.
From its source in Lake Itasca, 1,460 feet above mean sea level, the Mississippi River follows a semicircular 376 mile course to where it leaves the watershed at an altitude of 1,150 feet. The origin of the river is in glacial moraine. The river flows through end moraines and rolling till plains, across an extensive outwash plain occupied by large reservoir lakes, and finally across an extensive marshy plain which is the bed of an ancient glacial lake.
Glacial deposits in the watershed include till, lenses of sand and gravel in till, outwash deposits of sand and gravel, and lake deposits of fine sand, silt, and clay. Beneath the glacial drift is an uneven surface of Precambrian bedrock. Bedrock consists of igneous intrusives and metamorphosed sedimentary formations.
Water resources in the area are abundant. Lakes and streams occupy about 8 percent of the surface of the area. Ground-water supplies are available from glacial drift and from bedrock.
