Wisconsin v. Michigan

Background

Michigan originally sued to have the boundary with Wisconsin established, and the Court announced its decision in 1926 and entered a decree later that year. Wisconsin later filed suit in 1932 saying parts of that decree mistakenly failed to carry out the earlier decision for areas near the mouth of the Menominee River, Grassy Island, Sugar Island, and parts of Green Bay. A special master took evidence, viewed the area, proposed a detailed form of decree, and reported back to the Court following the Court’s May 20, 1935 directions.

Reasoning

The central question was whether the proposed decree accurately carried out the Court’s May 20, 1935 decision and properly described the boundary. The Court reviewed the master’s report, heard the States’ arguments, and overruled Wisconsin’s objections. It approved the special master’s technical boundary descriptions and modified the 1926 decree by striking the earlier wording and inserting the master’s detailed courses, azimuths, and distances. The Court also declared the tracts called Grassy Island and Sugar Island to belong to Michigan.

Real world impact

The decree now fixes and finally establishes the state line through the named rivers, harbor piers, Green Bay, Rock Island passage, and into Lake Michigan. That means the two States and local communities like Menominee and Marinette have a clear, court-defined boundary for control of those islands and waterways. The Court ordered the litigation costs divided equally between the States.