The Aleutian Range is a major mountain range located in southwest Alaska. It extends from Chakachamna Lake to Unimak Island, which is at the tip of the Alaska Peninsula. It includes all of the mountains of the Peninsula. The Aleutian Range is special because of its large number of active volcanoes, which are also part of the larger Aleutian Arc. The mainland part of the range is about 600 miles (1000 km) long. The Aleutian Islands are (geologically) a partially submerged western extension of the range that stretches for another 1,600 km (1000 mi). However the official designation "Aleutian Range" includes only the mainland peaks and the peaks on Unimak Island. The range is almost entirely roadless wilderness. Katmai National Park and Preserve, a large national park within the range, must be reached by boat or plane.
Katmai National Park and Preserve is an American national park and preserve in southwest Alaska, notable for the Valley of Ten Thousand Smokes and for its brown bears. The park and preserve encompass 4,093,077 acres, which is between the sizes of Connecticut and New Jersey. Most of the national park is a designated wilderness area. The park is named after Mount Katmai, its centerpiece stratovolcano. The park is located on the Alaska Peninsula, across from Kodiak Island, with headquarters in nearby King Salmon, about 290 miles (470 km) southwest of Anchorage. The area was first designated a national monument in 1918 to protect the area around the major 1912 volcanic eruption of Novarupta, which formed the Valley of Ten Thousand Smokes, a 40-square-mile (100 km2), 100-to-700-foot-deep pyroclastic flow. The park includes as many as 18 individual volcanoes, seven of which have been active since 1900.
Mount Katmai is a large active stratovolcano on the Alaska Peninsula in southern Alaska, located within Katmai National Park and Preserve. It is about 6.3 miles (10 km) in diameter with a central lake-filled caldera about two by three miles in size, formed during the Novarupta eruption of 1912. The caldera rim reaches a maximum elevation of 6,716 feet (2,047 m). In 1975 the surface of the crater lake was at an elevation of about 4,220 feet (1,286 m), and the estimated elevation of the caldera floor is about 3,400 ft (1,040 m). The mountain is located in Kodiak Island Borough, very close to its border with Lake and Peninsula Borough. The volcano has caused ten known fatalities due to gas exposure.
Aniakchak National Monument and Preserve is a U.S. National Monument and National Preserve, consisting of the region around the Aniakchak volcano on the Aleutian Range of south-western Alaska. It has erupted at least 40 times over the last 10,000 years. The 601,294-acre (243,335 ha) monument is one of the least-visited places in the National Park System due to its remote location and difficult weather. The area was proclaimed a National Monument on December 1, 1978, and established as a National Monument and Preserve on December 2, 1980. The National Monument encompasses 137,176 acres (55,513 ha) and the preserve 464,118 acres (187,822 ha). Visitation to Aniakchak is the lowest of all areas of the U.S. National Park System, according to the NPS, with only 100 documented recreational visits in 2017. Most visitors fly into Surprise Lake inside Aniakchak Crater, but the frequent fog and other adverse weather conditions make landing in the lake difficult. It is also possible to fly into the nearby village of Port Heiden and proceed overland to the Aniakchak Crater.
The Alaska Peninsula is a peninsula extending about 497 mi (800 km) to the southwest from the mainland of Alaska and ending in the Aleutian Islands. The peninsula separates the Pacific Ocean from Bristol Bay, an arm of the Bering Sea.
Redoubt Volcano, or Mount Redoubt, is an active stratovolcano in the largely volcanic Aleutian Range of the U.S. state of Alaska. Located at the head of the Chigmit Mountains subrange in Lake Clark National Park and Preserve, the mountain is just west of Cook Inlet, in the Kenai Peninsula Borough about 110 miles (180 km) southwest of Anchorage. At 10,197 feet (3,108 m), in just over 5 miles (8.0 km) Mount Redoubt attains 9,150 feet (2,790 m) of prominence over its surrounding terrain. It is the highest summit in the Aleutian Range. In 1976, Redoubt Volcano was designated as a National Natural Landmark by the National Park Service.
Shishaldin Volcano, or Mount Shishaldin, is a moderately active volcano on Unimak Island in the Aleutian Islands chain of Alaska in the United States. It is the highest mountain peak of the Aleutian Islands and rises about 10,000m from the bottom of the Aleutian Trench 140 miles south of the volcano. The volcano's topographic contour lines are nearly perfect circles above 6,500 feet (1,981 m). The lower north and south slopes are somewhat steeper than the lower eastern and western slopes. Only on the volcano's west flank between about 3500 to 6500 ft are small areas of rough topography which are remnants of an older collapsed volcano upon which Shishaldin is built. The volcano is the westernmost of three large stratovolcanoes along an east–west line in the eastern half of Unimak Island.
Mount Griggs, formerly known as Knife Peak Volcano, is a stratovolcano, which lies 10 km behind the volcanic arc defined by other Katmai group volcanoes. Although no historic eruptions have been reported from Mount Griggs, vigorously active fumaroles persist in a summit crater and along the upper southwest flank. The fumaroles on the southwest flank are the hottest, and some of the flank fumaroles can roar so loudly that they can be heard from the valley floor. The slopes of Mount Griggs are heavily mantled by fallout from the 1912 eruption of Novarupta volcano. The summit consists of three concentric craters, the lowest and largest of which contains a recent summit cone topped by two craters. The volume of the volcanic edifice is estimated at about 25 cubic kilometers (6.0 cu mi). Isotopic analysis indicates that the source of Griggs' magma is distinct from the other Katmai volcanoes.
Mount Pavlof or Pavlof Volcano is a stratovolcano of the Aleutian Range on the Alaska Peninsula. It has been one of the most active volcanoes in the United States since 1980, with eruptions recorded in 1980, 1981, 1983, 1986–1988, 1996–1997, 2007, 2013, twice in 2014, 2016, and is currently erupting as of August 2021. Basaltic andesite with SiO2 around 53% is the most common lava type. The volcano is monitored by the Alaska Volcano Observatory- a joint program of the United States Geological Survey (USGS), the Geophysical Institute of the University of Alaska Fairbanks (UAFGI), and the State of Alaska Division of Geological and Geophysical Surveys (ADGGS). With a threat score of 95, the threat from future eruptions is considered to be high; much of this threat comes from the possibility of disruption of nearby air routes by large releases of ash. The mountain currently has basic real-time monitoring, but the USGS would like to improve instrumentation at the site. The mountain shares a name with the nearby Pavlof Sister, which last erupted in 1786.
Mount Cleveland is a nearly symmetrical stratovolcano on the western end of Chuginadak Island, which is part of the Islands of Four Mountains just west of Umnak Island in the Fox Islands of the Aleutian Islands of Alaska. Mt. Cleveland is 5,675 ft (1,730 m) high, and one of the most active of the 75 or more volcanoes in the larger Aleutian Arc. Aleutian natives named the island after their fire goddess, Chuginadak, who they believed inhabited the volcano. In 1894 a team from the United States Coast and Geodetic Survey visited the island and gave Mount Cleveland its current name, after then-president Grover Cleveland.
Great Sitkin Island is a volcanic island in the Andreanof Islands of the Aleutian Islands of Alaska. The island covers a total area of 60 square miles (160 km2) and lies slightly north of a group of islands which are located between Adak Island and Atka Island.
Southwest Alaska is a region of the U.S. state of Alaska. The area is not exactly defined by any governmental administrative region(s); nor does it always have a clear geographic boundary.
Fourpeaked Mountain, also known as Fourpeaked Volcano, is an active stratovolcano located in the U.S. state of Alaska within Katmai National Park & Preserve. The volcano is nearly completely covered by Fourpeaked Glacier.
Becharof National Wildlife Refuge is a National Wildlife Refuge in the Aleutian Range of the Alaska Peninsula of southwestern Alaska. It is adjacent to Katmai National Park and Preserve. This national wildlife refuge, which covers an area of 1,200,000 acres (4,900 km2), was established in 1980 to conserve major brown bears, salmon, migratory birds, caribou, marine birds, and mammals and to comply with treaty obligations. It lies primarily in the east-central part of Lake and Peninsula Borough, but extends eastward into the mainland portion of Kodiak Island Borough. The refuge is administered from offices in King Salmon.
The Aleutian Arc is a large volcanic arc of islands extending from the Southwest tip of the U.S. state of Alaska to the Kamchatka Peninsula of the Russian Federation.
The Alaska Peninsula montane taiga is a taiga and boreal forests ecoregion, located in Alaska, and defined by the World Wildlife Fund (WWF) categorization system.
Kejulik Volcano, also known as Mount Kejulik or the Kejulik Pinnacles, are highly eroded remnants of an andesitic stratovolcano located in the southwestern Kejulik Mountains within the Aleutian Range near Becharof Lake. The volcano lies on the border of Katmai National Park and Preserve and the Becharof National Wildlife Refuge, about 30 miles southwest of Mount Katmai. Little information is available regarding Kejulik, according to the Alaska Volcano Observatory, and any possible volcanic activity is currently unknown.
Mount Aniakchak is a volcano on the western Alaska Peninsula. Part of the Aleutian Volcanic Arc, it was formed by the subduction of the oceanic Pacific Plate under the North American Plate. Aniakchak is a 10 kilometers (6.2 mi) wide caldera with a break to the northeast. The caldera contains Surprise Lake and numerous volcanic cones, maars and craters, including Vent Mountain. The volcano has erupted mainly calc-alkaline rocks ranging from basalt to rhyolite.
