Wisconsin Borders: States, Map & Complete Guide

Michigan and Wisconsin share a unique border relationship. The two states meet across Lake Michigan (Michigan's western shore faces Wisconsin's eastern shore) and also share a short land border in northern Wisconsin.

Wisconsin and Michigan share a small land border of about 70 miles in the Upper Peninsula region where the Menominee and Montreal Rivers form natural boundaries. This border exists because Michigan's Upper Peninsula sits west of Wisconsin's northern tip. Wisconsin counties along this border include Marinette and Florence. On the Michigan side, Menominee, Dickinson, Iron, and Gogebic counties touch Wisconsin. The rest of the Michigan-Wisconsin relationship is across Lake Michigan, where they face each other across the water.

Illinois forms Wisconsin's entire southern border. The boundary follows a straight east-west surveyed line across the bottom of the state.

The Wisconsin-Illinois border extends for about 185 miles from Lake Michigan in the east to the Mississippi River in the west. The border follows a surveyed parallel line established in the early 1800s. Wisconsin counties along this border include Kenosha, Racine, Walworth, Rock, Green, Lafayette, Iowa, and Grant. On the Illinois side, Lake, McHenry, Boone, Winnebago, Stephenson, and Jo Daviess counties sit along this border. The border region includes suburban areas near Chicago in the east and agricultural land in the west.

Iowa and Wisconsin are separated entirely by the Mississippi River in Wisconsin's southwestern corner. This short river boundary connects Wisconsin to the Upper Midwest.

The Wisconsin-Iowa border follows the Mississippi River for about 110 miles from Minnesota in the north to Illinois in the south. The entire border is a water boundary with the Mississippi forming a natural division. Wisconsin counties along this border include Grant, Crawford, and Vernon. The scenic bluffs and valleys of the Driftless Area characterize both sides of this border. Prairie du Chien, Wisconsin sits on this river border.

Minnesota and Wisconsin are separated by rivers along Wisconsin's western edge. The St. Croix River forms the border in the north, while the Mississippi River creates the boundary in the south.

The Wisconsin-Minnesota border follows rivers for about 260 miles from Lake Superior in the north to Iowa in the south. The St. Croix River and its tributary the Namekagon River form the northern section for about 150 miles, while the Mississippi River creates the southern section for about 110 miles. Wisconsin counties along this border include Douglas, Burnett, Polk, St. Croix, Pierce, Pepin, Buffalo, Trempealeau, La Crosse, Vernon, and Crawford. The Twin Cities area (Minneapolis-St. Paul) sits across the river from western Wisconsin communities. The St. Croix National Scenic Riverway protects the northern border region.

Lake Superior forms Wisconsin's northern boundary from Minnesota in the west to Michigan in the east. This is the largest freshwater lake in the world by surface area.

Wisconsin's Lake Superior coastline extends about 190 miles along the southern shore of the lake. The Apostle Islands, a group of 22 islands, sit in Lake Superior just off Wisconsin's Bayfield Peninsula and are protected as a national lakeshore. Wisconsin counties with Lake Superior shoreline include Douglas, Bayfield, and Ashland. Superior, Wisconsin sits at the western end of the lake where it meets Minnesota. The lake provides Wisconsin with deep-water port access and scenic northern coastline.

Lake Michigan forms Wisconsin's entire eastern boundary from Michigan in the north to Illinois in the south. This is the only Great Lake located entirely within the United States.

Wisconsin's Lake Michigan coastline stretches about 320 miles along the western shore of the lake. Wisconsin counties with Lake Michigan shoreline include Door, Kewaunee, Manitowoc, Sheboygan, Ozaukee, Milwaukee, and Racine. Door County and its peninsula separate Green Bay from the main body of Lake Michigan. Milwaukee, Wisconsin's largest city, sits on Lake Michigan's western shore. The lake has been crucial for shipping, fishing, and commerce since Wisconsin's early development. Popular beaches and resort towns dot the coastline.