Subsequently, Middle Island was purchased in 1999 by the Nature Conservancy of Canada, and then donated to the Canadian national park system on September 6, 2000.

The island is part of an archipelago across western Lake Erie, providing a natural migratory corridor for birds and other animals.

[5] During Prohibition, the island was a way station for alcohol en route to the United States on the south shore of Lake Erie.

Gangster Joe Roscoe acquired part of the island and built a seven-bedroom "clubhouse" that became the centre of rum-running activity.

[6] In the years after 1933, after the ratification of the Twenty-first Amendment to the United States Constitution resulted in the repeal of the Volstead Act, the hotel drew as many as 200 visitors a day in peak season.

Interest in preserving the island prompted a 1982 study by Parks Canada, which recommended naming it a national natural landmark.

A conservation group, Carolinian Canada Coalition, named Middle Island one of 38 critical unprotected sites in its effort to preserve remnants of Ontario's southern forests.