The Ahklun Mountains have many lakes, some more than 1,300 feet (400m) deep.[3] The mountains cover approximately 80 percent of the Togiak National Wildlife Refuge. The refuge also contains tundra and coastal plains.[4]
Environment
The Ahklun Mountains are dominated by alpine tundra, heath, and barrens, while moist sedge-tussock meadows occur in valley bottoms. Black spruce forest occurs on some hills and ridges. Forests of white spruce, paper birch, and alder cover the low hills along the major rivers.[5]Blackpoll warblers are common breeders in conifer stands in river valleys. Beaver are abundant, supporting a large annual harvest. Sockeye salmon are the most abundant fish. Chum, king, silver salmon, and rainbow trout are also numerous.[5] The average annual precipitation ranges from 19 to 25 inches (480 to 640mm), while the average annual temperature ranges from 29 to 33°F (−2 to 1°C). The growing season extends approximately from May 15 to September 10.[5]
The glaciers were first mapped by the U.S. Geological Survey, who used photogrammetry methods based on a 1972 series of aerial photos, revealing the presence of 116 glaciers. In 2006, 109 of these glaciers were resurveyed with the existence of 97 verified and 12 thought to have disappeared. This showed that over just three decades there had been a large decrease in the amount of land area covered by glacial ice in these mountains. The scientific community has long recognized the importance of glaciers as indicators of climatic change.[2]
In 2015, researchers analyzed aerial and satellite images from 1957, 1984, and 2009. They found that 10 out of 109 of the glaciers of the Ahklun Mountains originally mapped by the U.S. Geological Survey in the 1970s had completely disappeared.[6] They also compared the size of the glaciers using aerial photographs and satellite images and found that the glaciers had lost about 50 percent of their total area.[6] At this rate of melting, they predict that all of the glaciers in the Ahklun Mountains will be gone by the end of this century.[6]
Geological evidence show that during the Pleistocene era there were repeated glaciations that have carved out a large number of valley troughs. On the eastern side, these troughs contain networks of glacial lakes, some that are over 1,300 feet (400m) deep and are dammed by terminal moraines.[3] On the southern and western side, the valleys are broader and are interspersed with rolling uplands pierced by rugged massifs.[3]
Lowlands
In the lowlands, areas not reached by the glaciation, the principal geographic features are the moraines and ridges formed by thrusting ice.[3]
The Last Glacial Period (LGP), also known as the Last glacial cycle, occurred from the end of the Last Interglacial to the beginning of the Holocene, c. 115,000 – c. 11,700 years ago, and thus corresponds to most of the timespan of the Late Pleistocene.
The Wallowa Mountains are a mountain range located in the Columbia Plateau of northeastern Oregon in the United States. The range runs approximately 40 miles (64 km) northwest to southeast in southwestern Wallowa County and eastern Union County between the Blue Mountains to the west and the Snake River to the east. The range is sometimes considered to be an eastern spur of the Blue Mountains, and it is known as the "Alps of Oregon". Much of the range is designated as the Eagle Cap Wilderness, part of the Wallowa–Whitman National Forest.
Glacial landforms are landforms created by the action of glaciers. Most of today's glacial landforms were created by the movement of large ice sheets during the Quaternary glaciations. Some areas, like Fennoscandia and the southern Andes, have extensive occurrences of glacial landforms; other areas, such as the Sahara, display rare and very old fossil glacial landforms.
Selawik National Wildlife Refuge in northwest Alaska in the Waring Mountains was officially established in 1980 with the passage of the Alaska National Interest Lands Conservation Act (ANILCA).
Bow Valley Provincial Park is a provincial park in Alberta, Canada. Established in 1959 in the arch of the Bow River at its confluence with the Kananaskis River, the park is one park of many within the Kananaskis Country park system.
The Sawtooth Wilderness is a federally-protected wilderness area that covers 217,088 acres (87,852 ha) of the state of Idaho. Managed by the U.S. Forest Service in the U.S. Department of Agriculture, it was designated the Sawtooth Primitive Area in 1937 to preserve the scenic beauty of the Sawtooth Mountains. On August 22, 1972 Public Law 92-400 designated the Primitive Area as the Sawtooth Wilderness and part of the newly created Sawtooth National Recreation Area. As part of the National Wilderness Preservation System, the Sawtooth Wilderness is an area where human development and use are restricted and people are to remain only visitors. According to the United States Environmental Protection Agency, the Sawtooth Wilderness has some of the clearest air in the lower 48 states.
Misty Fjords National Monument is a national monument and wilderness area administered by the U.S. Forest Service as part of the Tongass National Forest. Misty Fiords is about 40 miles (64 km) east of Ketchikan, Alaska, along the Inside Passage coast in extreme southeastern Alaska, comprising 2,294,343 acres (928,488 ha) of Tongass National Forest in Alaska's Panhandle. All but 151,832 acres (61,444 ha) are designated as wilderness.
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.
The Kanektok River is a 75-mile (121 km) stream in southwestern Alaska in the United States. Beginning in the Ahklun Mountains at Kagati and Pegati lakes, it flows westward into Kuskokwim Bay on the Bering Sea at the city of Quinhagak. Almost all of the river's course lies within the Togiak National Wildlife Refuge. The Quinhagak Village Corporation owns the land bordering the lowermost 17 miles (27 km) of the river.
U-shaped valleys, also called trough valleys or glacial troughs, are formed by the process of glaciation. They are characteristic of mountain glaciation in particular. They have a characteristic U shape in cross-section, with steep, straight sides and a flat or rounded bottom. Glaciated valleys are formed when a glacier travels across and down a slope, carving the valley by the action of scouring. When the ice recedes or thaws, the valley remains, often littered with small boulders that were transported within the ice, called glacial till or glacial erratic.
The Sawtooth Range is a mountain range of the Rocky Mountains in central Idaho, United States, reaching a maximum elevation of 10,751 feet (3,277 m) at the summit of Thompson Peak. It encompasses an area of 678 square miles (1,756 km2) spanning parts of Custer, Boise, Blaine, and Elmore counties, and is bordered to the east by the Sawtooth Valley. Much of the mountain range is within the Sawtooth Wilderness, part of the Sawtooth National Recreation Area and Sawtooth National Forest.
Bonanza Peak is a tall peak in the North Cascades in the U.S. state of Washington and the Glacier Peak Wilderness of the Wenatchee National Forest. At 9,516 feet (2,900 m) in elevation, it is the highest point in Chelan County, and the highest non-volcanic peak in Washington. and the Cascade Range as a whole. Bonanza Peak's prominence is 3,711 feet (1,131 m), making it the 26th most prominent peak in Washington. The nearest higher peak is Glacier Peak, 14.4 miles (23.2 km) to the southwest.
Togiak National Wildlife Refuge is in the Dillingham and Bethel Census Areas, Alaska. It is dominated by the Ahklun Mountains in the north and the cold waters of Bristol Bay to the south. The natural forces that have shaped this land range from the violent and powerful to the geologically patient. Earthquakes and volcanoes filled the former role, and their marks can still be found, but it was the gradual advance and retreat of glacial ice that carved many of the physical features of this refuge.
Chimney Rock is a mountain located in the Alpine Lakes Wilderness of the Central Cascade Range in western Washington, United States. The mountain has two main summits, a northeast spire and a central spire, as well as a minor south peak. Situated 10 miles NNE of Snoqualmie Pass, with its craggy appearance Chimney Rock is the most distinctive peak on the crest dividing the Snoqualmie River and Yakima River drainage areas. Lemah Mountain is to the south on the crest, and Summit Chief Mountain to the northeast. Overcoat Peak is off the main ridge just to the north of Chimney Rock. The mountain has three glaciers: the Overcoat Glacier on the north, the Chimney Glacier on the south and east, and an unnamed glacier on the east side of the North Peak.
The Beringia upland tundra is a mountainous tundra ecoregion of North America, on the west coast of Alaska.
Lake Atna was a prehistoric proglacial lake that initially formed approximately 58 ka in the Copper River Basin, an area roughly centered around 245 km (152 mi) northeast of modern-day Anchorage, Alaska. The lake formed, and dispersed, during the Wisconsin glaciation. The lake existed in several forms, with several prominent shorelines observable in modern geology. At its greatest extent, the lake surface area was approximately half the size of modern-day Lake Ontario, and possibly much larger. The basin of the lake lay within an area bordered by the Alaska Range to the north, the Wrangell Mountains to the east, the Chugach Mountains to the south, and the Talkeetna Mountains to the west.
Napeequa Peak is an 8,073-foot (2,461-metre) pyramidal mountain summit located in the Glacier Peak Wilderness of the North Cascades in Washington state. The mountain is situated on the crest of the Cascade Range, on the shared border of Snohomish County and Chelan County, also straddling the boundary between the Mount Baker-Snoqualmie National Forest and the Wenatchee National Forest. Its nearest neighbor is Cirque Mountain, 0.3 mi (0.48 km) to the north, and the nearest higher peak is Buck Mountain, 2.56 mi (4.12 km) to the east-southeast. Precipitation runoff from the peak drains east to the headwaters of Napeequa River; or west into the Suiattle River. The mountain's name is taken from the river's name, which was applied by Albert Hale Sylvester (1871-1944), a pioneer surveyor, explorer, topographer, and forest supervisor in the Cascades.
Arrowhead Mountain is a 6,030 ft (1,840 m) mountain summit located in Chelan County of Washington state. It is situated 6 mi (9.7 km) east of Stevens Pass, on the boundary of Alpine Lakes Wilderness, on land managed by the Okanogan–Wenatchee National Forest. Arrowhead Mountain is part of the Chiwaukum Mountains, which are a subset of the Cascade Range. Its nearest higher neighbor is Jim Hill Mountain, 2.5 mi (4.0 km) to the southwest. Precipitation runoff from the peak drains into tributaries of Nason Creek, which in turn is a tributary of the Wenatchee River. This mountain was named by Albert Hale Sylvester (1871–1944), a pioneering surveyor, explorer, topographer, and forest supervisor who named hundreds of natural features in the Cascades.
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Dip Top Peak is a 7,291-foot-elevation mountain summit located in the Alpine Lakes Wilderness in eastern King County of Washington state. It is part of the Cascade Range and is set on land managed by Mount Baker-Snoqualmie National Forest. The peak is situated 1.25 mi (2.01 km) north of Mount Daniel, and less than one mile south of Jade Lake. Precipitation runoff from the mountain drains into East Fork Foss River, which is a tributary of the Skykomish River. The summit saddle has two rock horns, of which the higher southwest peak is the true summit. The first ascent was made August 1950 by Bill and Gene Prater. In the early 1970s, brothers Gene and Bill Prater created the modern aluminum snowshoe known today, and sold them via Bill's "Sherpa Snowshoes" company, which proved very popular.
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