Three States Bordered by the Mississippi River: Minnesota, Iowa, Wisconsin

The Mississippi River forms a significant portion of the eastern border for three Upper Midwest states:

1. Minnesota: The river's source (Lake Itasca) is here. It forms the state's eastern border from the Twin Cities downstream to the Iowa border (~300 mi).
2. Iowa: Entire eastern border (~310 mi) is the Mississippi, separating Iowa from Illinois and Wisconsin.
3. Wisconsin: Western border (~260 mi) is the Mississippi, separating Wisconsin from Iowa and Minnesota.

Beyond the Three

The Mississippi also borders or flows through Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana—but for those states, it's a western or internal boundary, not an eastern one. The "three states" framing typically refers to the Upper Mississippi's role as a clean, north-south state line.

Historical Significance

These borders were established by the Northwest Ordinance (1787) and subsequent territorial acts, using the river as a clear natural demarcation before survey grids reached the region.