Split Rock Lighthouse

Split Rock Lighthouse stands on the North Shore of Lake Superior in Minnesota, southwest of Silver Bay. Engineer Ralph Russell Tinkham designed it, and the United States Lighthouse Service finished it in 1910. The octagonal tower is a steel-framed brick building with concrete trim, set into the rock of a 133-foot cliff that waves have cut from a diabase sill. When it was built the area had no roads, so every load of materials came by water and was lifted up the cliff by crane.

The lens at the top is a third-order Fresnel lens made in Paris. The tower was meant for a larger second-order lens, but the construction went over budget and there was only enough money left for the smaller one. The lens floats on a bearing of liquid mercury, so it turns almost without friction, driven by a clockwork mechanism powered by weights that run down the center of the tower and are cranked back to the top.

The lighthouse was built in response to the Mataafa Storm of 1905, when 29 ships were lost or damaged on Lake Superior. One of the wrecks, the Madeira, lies just north of the lighthouse. The lamp was first lit on July 31, 1910. The place soon became an attraction for sailors and excursion boats, and in 1924 a road, now Minnesota State Highway 61, was built to give land access. The station was electrified in 1940 and also had a fog signal, which was discontinued in 1961.

The U.S. Coast Guard retired the light in 1969. Today the lighthouse is part of Split Rock Lighthouse State Park and is operated by the Minnesota Historical Society. The site includes the original tower and lens, the fog signal building, the oil house and three keepers' houses, restored to look as they did in the late 1920s. It joined the National Register of Historic Places in 1969 and became a National Historic Landmark in 2011. Every November 10 the light is lit again in memory of the SS Edmund Fitzgerald, which sank on that date in 1975. The lighthouse also appears in the 2013 film The Great Gatsby.