A beacon at Cape Spencer was requested as early as 1906, but it wasn’t until 1912 that this rocky region received its first light - an unmanned acetylene lantern. Funds for a lighthouse to properly mark Cape Spencer were later granted, and construction commenced in May 1924. A single-story reinforced concrete building (51’ x 62’) was built at the summit of the rocky mass to house both the fog signal equipment and the keepers. From the center of the structure’s roof, a 14-by-14-foot tower rose another twenty-five feet.
The Coast Guard removed the Fresnel lens from Cape Spencer in 1974, the same year in which the lighthouse was automated. The small lighthouse, perched atop the seventy-foot-tall rock, is still considered an important navigational aid and receives regular Coast Guard visits.