The passage was preferred as safer than being on the open lake—so much so that 1,000 ships passed each day, carrying people and commerce—the passageway nonetheless was treacherous.

A report to the Secretary of the Treasury noted that the island offered shelter from storms and fuel for steamships.

The report opined that it was the only all weather harbor admitting large vessels in the 300 mile direct route from the Straits of Mackinac to Chicago.

"Before the light went on, a man who had been in a boat on a storm-tossed lake in the area of South Manitou recounted the sense of terror he felt.

Keeper Aaron Sheridan, his wife and their infant on March 15, 1878 died in a boating accident near the light.

In the 1980s the towers foundation was reinforced to protect it from erosion at a time of high lake levels which threatened to topple the structure.