Mary Island is the site of a historic lighthouse located between Felice Strait to the west and Revillagigedo Channel to the east, about 64 miles (103 km) north-northwest of Prince Rupert, British Columbia and 25 miles (40 km) southeast of Ketchikan, Alaska. Mary Island was named by W.E. George, a local ship’s pilot, after the daughter of Admiral John A. Winslow, who cruised past the island with her father in 1872 aboard the USS Saranac. The island is formed by rocks representing the Annette subterrane which is a constituent of the Alexander terrane which forms most of the Alexander Archipelago of Southeast Alaska. Most of Mary Island consists of metamorphosed sedimentary rocks that developed during the Silurian or Ordovician periods; however, the portion underlying the lighthouse is an intrusive called the Metlakatla pluton.
The Mary Island lighthouse is all that remains of a larger station that historically included a customs house and a now abandoned community located in Custom House Cove on the northeast coast of the island. Following the Alaska Purchase in 1867, the U.S. Government expected the area of Revillagigedo Channel to become the main entryway to Alaska from the south and the first stopping place for vessels arriving from Canada. In 1892, a customs house to handle ship traffic from British Columbia into Alaska was built on Mary Island and the Lighthouse Board immediately petitioned Congress to provide funds for a lighthouse. But funds for the lighthouse were delayed until the Klondike Gold Rush of 1897-98 created a dramatic spike in maritime traffic. Funds were appropriated in 1902, but by then the customs house had already been moved to the small community of Ketchikan, about 26 miles (42 km) to the northwest.
The Mary Island Light Station, Alaska’s fourth lighthouse, was built in 1902, although it was lit for the first time on July 15, 1903. The original lighthouse consisted of an octagonal, one-story wooden building with a smaller octagonal tower extending from its center to a height of nearly 50 feet (15 m). The black cylindrical lantern room atop the tower housed a fourth-order Chance Brothers Fresnel lens that beamed a fixed white light. In 1926, the light and in 1931, a radio beacon navigation aid was installed. In 1936, the Lighthouse Service upgraded the structure with a reinforced concrete tower in an art deco style. The base of the tower connected to a flat-roofed building, which housed air compressors and electric generators on its main floor, and fuel, supplies and a heating plant in its basement. By 1961, the light station consisted of a boathouse, oil houses, a cart-house, and several light keepers dwellings. Today, all of this is gone except for the lighthouse itself, and it is a concrete shell with a solar-powered light. Read more here and here. Explore more of Mary Island and Revillagigedo Channel here:
