Fisher Caldera, also known as Mount Fisher and Fisher Volcano, is a large volcanic caldera, measuring about 6.8 miles (11 km) by 11 miles (18 km), located on Unimak Island in the Aleutian Islands of Alaska.^[1] Formed by the destructive eruption of an andesitic stratovolcano about 9,100 years ago,^[1] it contains three crater lakes, one 2 miles (3.2 km) wide and two others about 1.5 miles (2.4 km) wide. Small peaks rising 2,000 feet (600 m) and 2,031 feet (619 m) are also present in the caldera. Fisher Caldera is located just 13 miles (21 km) from the Mount Westdahl volcano.

Fisher Caldera
Satellite picture of Unimak Island with Fisher Caldera
Highest point
Elevation	3,648 ft (1,112 m)[1]
Coordinates	54°40′N 164°23′W / 54.667°N 164.383°W / 54.667; -164.383
Geography
Location	Unimak Island, Alaska, United States
Parent range	Aleutian Range
Topo map	USGS Unimak C4
Geology
Mountain type	Stratovolcano remnant
Volcanic arc/belt	Aleutian Arc
Last eruption	August 1830

The largest volcanic eruption on Earth during the Holocene Epoch (the last 11,700 years) occurred at Fisher Caldera in 8700 BCE.^[2]