Galloo Island Light stands on the southwestern end of Galloo Island in eastern Lake Ontario, where its exposed position near Sackets Harbor and the Saint Lawrence River approaches made it a crucial navigational warning for ships threading nearby islands and shoals. Authorized in 1818 and first established in 1820, it was the first lighthouse erected on Lake Ontario. The present gray-stone tower, completed in 1867, displays a fixed white light visible up to 15 miles and used a steam whistle in fog. Long staffed despite the island’s isolation and lack of a harbor, the station was automated in 1963 and listed on the National Register of Historic Places in 1983.