Ontonagon Lighthouse

Ontonagon, Michigan, USA

Lake Superior

This light was built in 1867 to replace an earlier light dating to 1852. It was the fifth lighthouse built on Lake Superior, and originally cost $5,000 to build. It features a 34-foot high tower. The addition on the back was added in 1890. The light was decommissioned in 1964 after a new tower light and fog signal were installed.

It is located on the south side of the Ontonagon River near its mouth. It sits inland; there is also another light on the nearby pier that juts out into Lake Superior. Located on private property and no longer in service, this light is sometimes obscured by large coal piles that serve the adjacent paper mill.

The Ontonagon Light once had a Fourth Order Fresnel lens. It was removed and may be seen at the Ontonagon County Historical Museum in downtown Ontonagon. 19 1975, this lighthouse was placed on the National Register of Historic Places.

The Fresnel lens is named after Augustin Fresnel, who invented it in France in the 1820's. His design uses a system of circular prisms to intensify and focus the light from a single lamp. The prisms work in such a way that instead of the light going out in all directions, it is bent and the beams go out parallel to the water. This Fourth Order lens, removed from the Ontonagon Lighthouse, is displayed at the Historical Museum in Ontonagon, Michigan.