Mutton Cove is an embayment on Unalaska Island, about 0.3 miles (0.5 km) across, on the northern shore of Chernofski Harbor, about 64 miles (103 km) north-east of Nikolski and 53 miles (85 km) south-west of Dutch Harbor, Alaska. The cove forms a harbor protected by Observatory Point to the west. It was named in 1937 by the US Coast and Geodetic Survey, presumably for a sheep ranch and transfer station operating there at the time. Unalaska Island, like all of the Aleutian Arc, is volcanic. The geology of the south-western tip consists mostly of the Unalaska Formation, which comprises slightly metamorphosed andesite and basalt extrusive rocks and sills, as well as sedimentary rocks ranging in coarseness from argillite to conglomerate.

Chernofski Harbor extends south-east into Unalaska Island for four miles (6.4 km) from Umnak Pass, an important channel between the Bering Sea and the North Pacific Ocean. The embayment was the site of an ancient Unangan Aleut village occupied for more than 2,000 years before Russian contact. The harbor was presumably named after the village, which was given the Russian family name Chernof. In 1790 Lieutenant Gavril Sarichev was treated by a shaman in Chernofski who performed a healing ritual; the village name first appeared on a Russian chart published in 1792. In 1831 the Russian priest Ioann Veniaminov described the village as consisting of four huts. In 1848 the Chapel of the Epiphany of Our Lord was built. In 1861, when Friar Innokentii Shayashnikov visited, the chapel roof had blown away during a storm. In 1919 the Umnak Livestock Company started a sheep ranch on the south-west coast of Chernofski Harbor at Mailboat Cove. In 1928 the village was abandoned after many residents succumbed to influenza and other diseases. The few remaining people dismantled the chapel and moved items of religious value to the Kashega church. Several dozen residents moved to Kashega; others, including the chief, moved to the village of Unalaska.

In December 1941 the US Army began construction of Fort Glenn on nearby Umnak Island, and Chernofski provided the nearest natural harbour for transhipment of supplies. In January 1942 Chernofski Harbor was officially established as part of the Fort Mears military installation at Dutch Harbor on Amaknak Island. To support Fort Glenn operations, a main pier, three barge landings, a repair dock and several support buildings and infrastructure were built along the perimeter of Mutton Cove. By 1945 Chernofski Harbor was no longer needed for the war effort, and the military vacated the site. In 1949 some 66,415 acres (26,877 ha) of the former military facility were relinquished to the Bureau of Land Management; the remaining 2,885 acres (1,168 ha) were transferred in 1955. The ruins in Mutton Cove consist of docks, a coal pile, buildings, communications towers, a submarine net, barbed wire, petroleum, oil and lubricant drums, pipelines and batteries. Most of the remaining debris can be found on both sides of Mutton Cove and on Cutter Point. Read more here and here. Explore more of Mutton Cove and Chernofski Harbor here: