Port Althorp is an embayment and the site of a historical salmon cannery on the north coast of Chichagof Island, about 155 miles (250 km) southeast of Yakutat and 29 miles (47 km) southwest of Gustavus, Alaska. The bay was named in 1794 by Captain George Vancouver after George J. Spencer, 2nd Earl Spencer, also known as Viscount Althorp from 1765 to 1783 and First Lord of the Admiralty from 1794 to 1801. The deep bay extends southeast for 5 miles (8 km) from the George Islands and lies between the Inian Peninsula to the east and the Althorp Peninsula to the west. Chichagof Island is part of the Alexander Archipelago in Southeast Alaska, directly north of Baranof Island and separated by Peril Strait. It is bounded by Chatham Strait to the east, Icy Strait to the northeast, Cross Sound to the northwest, and the Gulf of Alaska to the west. During the Middle Mesozoic period, Southeast Alaska was involved in the oblique subduction of the Pacific Plate beneath the North American Plate. In the Early Cenozoic, this subduction boundary evolved into a primarily transform boundary. On Chichagof Island, this tectonic history is evident in a complex pattern of thrust, oblique-slip, and strike-slip faults. These major faults have divided the island’s geology into three tectonostratigraphic terranes: Alexander, Wrangellia, and Chugach. Port Althorp is chiefly surrounded by the Chugach terrane, a thick accretionary complex dominated by Paleocene trench fill turbidites, likely derived from a volcano-plutonic complex that lithified into graywacke. The bedrock at Port Althorp is diorite, which intruded the Chugach terrane as a pluton during the Late Jurassic or Early Cretaceous. This bedrock is overlain by Quaternary alluvial and glacial deposits, creating relatively level ground along the shore.

Chichagof Island was among the last large islands in Southeast Alaska to be settled by Euro-Americans. Before 1800, little is known about its history. The Huna Tlingit, or Sheet’ka Kwaan, traditionally occupied this region. Both oral history and scientific findings confirm their ancestors lived in Glacier Bay long before the last glacier advance. This area, known as S’e Shuyee, or ‘edge of the glacial silt,’ was their home. Around 1700, a glacier surged, overrunning their settlements. The clans survived by dispersing across Icy Strait, Excursion Inlet, and northern Chichagof Island, eventually settling in the village of Xunniyaa, meaning ‘shelter from the north wind,’ now called Hoonah. Historically, Chichagof Island has had various names. Early Russian maps called it Sitka Island, Chicagos Island, and Tchitchagoff Island. In 1778, Captain James Cook sailed along the coast. Cape Cross was named for a cross on Cook’s chart marking his position on May 3, 1778. Cross Sound was likely named for its proximity to Cape Cross. In 1794, Captain George Vancouver, aboard HMS Discovery and HMS Chatham, entered Cross Sound after returning from Prince William Sound. He spent three weeks mapping Port Althorp, while Lieutenant Joseph Whidbey led three small boats to explore Icy Strait and Lynn Canal. The island, originally known to the Russians as Yakobi or Jakobi, was renamed in 1805 by Yuri Lysianskyi in honor of Admiral Vasili Y. Chichagov. In 1905, a rich gold-bearing vein, later named the Chichagof vein, was discovered, leading to the founding of the mining town of Chichagof. The salmon industry rapidly expanded just before and during World War I, as the federal government purchased canned salmon to feed soldiers. In 1918, the Deep Sea Salmon Company established a new cannery at Port Althorp, using equipment from its former facility in Knik Arm. This was one of 16 new canneries that began operations in Alaska that year. Port Althorp was chosen for its proximity to Cross Sound, where migrating salmon could be easily intercepted. Rising salmon prices fueled the cannery’s expansion, and during the 1920s and 1930s, it became one of the largest facilities in Southeast Alaska. On August 4, 1940, a fire destroyed most of the buildings, and the complex was not rebuilt.

In 1930, the only significant military presence in Alaska was a garrison of 400 US Army troops at Fort William Seward near Haines. As Japan pursued imperial ambitions, American military planners recognized the potential for Pacific warfare. War Plan Orange was developed, with a perimeter extending from the Panama Canal Zone in the south to the Territory of Hawaii in the west and the Territory of Alaska in the north. Naval aircraft and surface vessels would deploy from bases at these triangle vertices to intercept enemy forces before they could threaten the contiguous United States. In the latter half of the 1930s, squadrons of Navy P2Y-3 flying boats and their support vessels, converted World War I destroyers, were stationed in Southeast Alaska bays and harbors for several months at a time. They conducted weekly round-trip patrols to Attu Island at the end of the Aleutians. In December 1938, the Naval planning board endorsed constructing three full Naval Air Stations in Alaska, at Sitka, Kodiak, and Dutch Harbor. A Washington-based consortium, Seims Drake Puget Sound, began work in late August 1939. In 1940, the contract expanded to include six smaller bases for each air station. Naval Air Station Sitka initially included dispersed bases at Annette Island, Port Armstrong, Port Althorp, Yakutat, Cordova, and Ketchikan. In 1942, the Navy transferred the Cordova and Ketchikan bases to the US Coast Guard. Most bases utilized pre-existing civilian structures. That year, the US Navy requisitioned the remains of the cannery at Port Althorp as a Navy Auxiliary Air Station. Usable buildings included a dock with a warehouse, separate bunkhouses for white and oriental employees, a mess hall and galley, cold storage, a watchman’s house, a building adjoining the scow ways, and fuel tanks for diesel and fuel oil. By 1943, 110 military personnel and four aircraft were stationed at Port Althorp to maintain daylight patrols of convoys headed to the military base at Excursion Inlet. After the war this infrastructure was no longer needed and the Navy decommissioned the facility on June 1, 19 44. Read more here and here. Explore more of Port Althorp and Chichagof Island here: