1985 Map of Passage Island

About this map

Passage Island stands as a lonely outpost within the northeastern reaches of Isle Royale National Park in Lake Superior. This 1985 survey captures the maritime infrastructure essential for navigating these northern waters, including a Lighthouse, Radio Towers, and a Heliport clustered on the island's southwestern end. The map also delineates the international boundary between Canada and the United States, as well as the provincial and state line separating Ontario and Michigan. Further east, the small cluster of the Gull Islands emerges from the water, marking some of the most remote territory in Houghton Twp. The topography is defined by the stark isolation of the islands, with soundings and depth curves indicating the underwater terrain of the surrounding lake.