Vehicle access to the island is via a ferry service at its northwestern tip, connecting east of Sault Ste.

The island was part of the Canada–United States border dispute settled by the Webster–Ashburton Treaty, and affirmed to be part of the United States when the treaty was signed August 9, 1842.

[2] In 1945 Sugar Island was nominated as a possible location for the headquarters of the United Nations.

The University of Michigan Biological Station operates the Chase Osborn Preserve, a 3,200-acre (13-square-kilometer) tract near the southern tip of the island.

The Preserve is named for Chase Osborn, an island resident who had been the governor of Michigan.