Cape Spencer was named by Captain George Vancouver during his exploration of Southeast Alaska in 1793-1794 in honor of George John Spencer who served as England’s First Lord of the Admiralty from 1794 to 1800. An unmanned acetylene light was placed here in 1912 but it was not until late 1925 that the manned lighthouse was constructed. The 25 foot tall Cape Spencer lighthouse tower contained a third-order Fresnel lens which produced a white light every fifteen seconds.
Access to the lighthouse was either by helicopter or a 16 foot skiff that was lowered by crane 60 feet to the water. The skiff would rendezvous with a waiting supply ship (which arrived every 2 to 4 weeks, weather permitting) and then return to the island to be lifted by the crane back up to the lighthouse.
The Cape Spencer Lighthouse was added to the National Register of Historic Places in 1975.