Cape Tanak is a headland on the north coast of Umnak Island in the Eastern Aleutian Islands between Cape Idak to the east and Ashishik Point to the west, about 64 miles (103 km) southwest of Dutch Harbor and 56 miles (90 km) northeast of Nikolski, Alaska. The name of the cape was first published in 1852 by Captain Mikhail Tebenkov of the Imperial Russian Navy, as ‘Cape Tanakh’, reputedly from the Unangan Aleut word ‘tanaq’, which according to Richard H. Geoghegan, means ‘place’. However, a different interpretation by Knut Bergsland suggests the name comes from the word ‘Tanaxsiqax’ meaning ‘made into land’, and may refer to the shoreline along the cape being extended seaward approximately 1 mile (1.6 km) during the first outburst flood from the Mount Okmok caldera between 1560 and 1010 years ago. Umnak Island is about 70 miles (113 km) long and one of the seven Fox Islands. The name of the island was reported in 1768 by Russian Captain Lieutenant Pyotr Krenitsyn and Lieutenant Mikhail Levashov. This island was called ‘Oomanak’ by Captain James Cook and ‘Umnak’ by Father Ivan Veniaminov.

Umnak Island is one of a rugged chain of active volcanoes between the Alaska Peninsula and Siberia. The island chain represents the southern margin of the Bering Land Bridge which facilitated the migration of ancient peoples to North America. The ancestors of present-day Unangan Aleuts settled in the islands and became genetically isolated from Eskimos and Athabaskans. The oldest known Aleut settlement is on Anangula Island, off the southwest coast of Umnak Island, and has been dated to about 8400 years ago. The first European explorers in Alaska were Russian fur traders who arrived in 1744 but did not have a major presence in the Eastern Aleutians until the 1780s when they began to conscript Aleut males to hunt sea otters. The hunters and their families were settled into permanent villages and converted to the Russian Orthodox faith. Cape Tanak is the site of a historical Aleut village called Egorkovskoi that, according to the geologist Constantin Grewingk, was destroyed by an eruption of Mount Okmok in 1817 while its inhabitants were hunting in the Pribilof Islands. They returned to find the place buried under enormous rocks and ashes, and subsequently moved the village to Inanudak Bay on the southwest coast of the island.

Okmok volcano is one of the most active calderas in North America and the Aleutians. During the historical period, documented eruptions took place in 1805, 1817, 1824–1830, 1878, 1899, 1945, 1958, 1997, and 2008. The largest of these took place in March 1817 when lava flows dammed a lake in the caldera which subsequently failed, causing a massive flood that destroyed Egorkovskoi. A cone began to grow after the eruption, which became the site of mostly effusive eruptions. The eruptions of 1945, 1958 and 1997 emplaced large lava flows on the caldera floor, partly overriding each other. The 1958 lava flow reached a length of 5 miles (8 km) and dammed a drainage to form a lake. On Saturday, July 12, 2008, Okmok Caldera erupted without warning, sending a plume of ash to 50,000 feet (15,000 m). A crater lake drained through a notch eroded in the northeast rim and the resulting flood transported tremendous volumes of sediment down the slope of the volcano to the sea at Cape Tanak. The remains of a fishing boat are partially buried on the beach at the mouth of the unnamed river that drained the caldera lake. Seasonal storms in the Bering Sea repeatedly expose and bury this wreck so that every year different parts of the ship are visible. Read more here and here. Explore more of Cape Tanak and Umnak Island here: