[1] It is bounded by the land masses of St. Joseph Island, Ontario at the northwest and Drummond Island, Michigan at the southeast, and by the water bodies the Saint Marys River and the De Tour Passage at the southwest and the North Channel at the northeast.

[5] Potagannissing Bay occupies the site of the rapid melting of a glacier at the end of the Wisconsin glaciation approximately 10,000 years before the present.

Few of the islands are permanently inhabited, but many are privately owned with summer cottages built upon them for the use of their owners.

The innumerable islands of the bay create opportunities for amateur exploring and sightseeing, and a sheltered coastline is rarely far away.

The piscatorial opportunities of the bay have drawn a significant population of fish-eating birdlife, including the great blue heron, osprey, and bald eagle.