The Brooks Range ( Gwich'in: ''Gwazhał'') is a

mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have aris ...

in far northern

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

stretching some from west to east across northern

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

into

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

Yukon Territory Yukon () is a territory of Canada, bordering British Columbia to the south, the Northwest Territories to the east, the Beaufort Sea to the north, and the U.S. state of Alaska to the west. It is Canada’s westernmost territory and the smallest ...

. Reaching a peak elevation of on Mount Isto, the range is believed to be approximately 126 million years old. In the United States, these mountains are considered a subrange of the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...

, whereas in Canada they are considered separate, as the northern border of the Rocky Mountains is considered to be the

Liard River The Liard River of the Boreal forest of Canada, North American boreal forest flows through Yukon, British Columbia and the Northwest Territories, Canada. Rising in the Saint Cyr Range of the Pelly Mountains in southeastern Yukon, it flows sout ...

far to the south in the province of

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

. While the range is mostly uninhabited, the

Dalton Highway The James W. Dalton Highway, usually referred to as the Dalton Highway (and signed as Alaska Route 11), is a road in Alaska. It begins at the Elliott Highway, north of Fairbanks, and ends at Deadhorse (an unincorporated community within t ...

and

Trans-Alaska Pipeline System The Trans-Alaska Pipeline System (TAPS) is an oil transportation system spanning Alaska, including the trans-Alaska crude-oil pipeline, 12 pump stations, several hundred miles of feeder pipelines, and the Valdez Marine Terminal. TAPS is one o ...

run through the Atigun Pass (1,415 m, 4,643 ft) on their way to the

oil field A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the prese ...

s at Prudhoe Bay on Alaska's North Slope. The

Alaska Native Alaska Natives (also known as Native Alaskans, Alaskan Indians, or Indigenous Alaskans) are the Indigenous peoples of the Americas, Indigenous peoples of Alaska that encompass a diverse arena of cultural and linguistic groups, including the I ...

villages of Anaktuvuk and Arctic Village, as well as the very small communities of Coldfoot, Wiseman, Bettles, and Chandalar, are the range's only settlements. In the far west, near the Wulik River in the De Long Mountains is the Red Dog mine, the largest zinc mine in the world. The range was named by the

United States Board on Geographic Names The United States Board on Geographic Names (BGN) is a Federal government of the United States, federal body operating under the United States Secretary of the Interior. The purpose of the board is to establish and maintain uniform usage of geogr ...

in 1925 after Alfred Hulse Brooks, chief

USGS The United States Geological Survey (USGS), founded as the Geological Survey, is an government agency, agency of the United States Department of the Interior, U.S. Department of the Interior whose work spans the disciplines of biology, geograp ...

geologist for Alaska from 1903 to 1924. Various historical records also referred to the range as the Arctic Mountains, Hooper Mountains, Meade Mountains and Meade River Mountains. The Canadian portion of the range is officially called the British Mountains. Ivvavik National Park is located in Canada's British Mountains.

Peaks

* Mount Isto * Mount Hubley * Mount Chamberlin * Mount Michelson at * The Gates of Kiev at , the highest point in the central part of the range * Black Mountain at , the highest point in the far western part of the range. * Mount Doonerak * Mount Igikpak * Frigid Crags West Gate * Boreal Mountain East Gate * Limestack Mountain * Cockedhat Mountain

History

Bob Marshall explored the North Fork Koyukuk River area of the range in 1929. He named Mount Doonerak, explaining "the name Doonerak I took from an Eskimo word which means a spirit or, as they would translate it, a devil." Marshall described the mountain as, a "towering, black, unscalable-looking giant, the highest peak in this section of the Brooks Range."

Ecology

The Brooks Range forms the northernmost drainage divide in North America, separating streams flowing into the Arctic Ocean and the North Pacific. The range roughly delineates the summer position of the Arctic front. It represents the northern extent of the

tree line The tree line is the edge of a habitat at which trees are capable of growing and beyond which they are not. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually low ...

, with little beyond isolated balsam poplar stands occurring north of the continental drainage divide. Trembling aspen and

white spruce White spruce is a common name for several species of spruce (''Picea'') and may refer to: * '' Picea engelmannii'', native to the Rocky Mountains and Cascade Mountains of the United States and Canada * ''Picea glauca ''Picea glauca'', the whi ...

also occur north of the Brooks Range, though they are limited to sites that have been disturbed by human activity. Southern slopes have some cover of black spruce, ''

Picea mariana ''Picea mariana'', the black spruce, is a North American species of spruce tree in the Pinaceae, pine family. It is widespread across Canada, found in all 10 provinces and all 3 Canadian Arctic Lands, territories. It is the official tree of Newfo ...

'', marking the northern limit of those trees. As the global mean temperature increases, tree line has been observed to move further north, changing the boundaries of where these trees are found. An increase in shrub abundance is also being experienced in areas which were previously dominated by tundra, impacting the ecology of the area. As one of the most remote and least-disturbed wildernesses of North America, the mountains are home to Dall sheep,

grizzly bear The grizzly bear (''Ursus arctos horribilis''), also known as the North American brown bear or simply grizzly, is a population or subspecies of the brown bear inhabiting North America. In addition to the mainland grizzly (''Ursus arctos horr ...

s, black bear,

gray wolf The wolf (''Canis lupus''; : wolves), also known as the grey wolf or gray wolf, is a canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, including the dog and dingo, though gr ...

moose The moose (: 'moose'; used in North America) or elk (: 'elk' or 'elks'; used in Eurasia) (''Alces alces'') is the world's tallest, largest and heaviest extant species of deer and the only species in the genus ''Alces''. It is also the tal ...

and

porcupine caribou The Porcupine caribou is a herd or ecotype of the mainland barren-ground caribou (''Rangifer arcticus arcticus'', Synonym (taxonomy), syn. ''R. tarandus groenlandicus''Harding LE (2022) Available names for Rangifer (Mammalia, Artiodactyla, Cervid ...

. In Alaska, the Western Arctic Caribou herd (490,000 strong in 2004) traverses the Brooks Range in its annual migration. The smaller Central Arctic

herd A herd is a social group of certain animals of the same species, either wild or domestic. The form of collective animal behavior associated with this is called '' herding''. These animals are known as gregarious animals. The term ''herd'' ...

(32,000 in 2002), as well as the 123,000 animal Porcupine Caribou herd, likewise migrate through the Brooks range on their annual journeys in and out of the Arctic National Wildlife Refuge. The migration path of the Porcupine Caribou herd is the longest of any terrestrial mammal on earth.

Paleontology

Because the rocks of the range were formed in an ancient seabed, the Brooks Range contains

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

s of

marine organism Marine life, sea life or ocean life is the collective ecological communities that encompass all aquatic animals, aquatic plant, plants, algae, marine fungi, fungi, marine protists, protists, single-celled marine microorganisms, microorganisms ...

s. In addition to the

coral Corals are colonial marine invertebrates within the subphylum Anthozoa of the phylum Cnidaria. They typically form compact Colony (biology), colonies of many identical individual polyp (zoology), polyps. Coral species include the important Coral ...

fossils shown,

trilobite Trilobites (; meaning "three-lobed entities") are extinction, extinct marine arthropods that form the class (biology), class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most succ ...

s and

brachiopod Brachiopods (), phylum (biology), phylum Brachiopoda, are a phylum of animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear e ...

s from the middle

Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...

have been found in the sandy

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

s of the Central Brooks Range. During the middle of the Cretaceous, the Brooks Range thrust belt underwent significant regional extension. Remains of a

woolly mammoth The woolly mammoth (''Mammuthus primigenius'') is an extinct species of mammoth that lived from the Middle Pleistocene until its extinction in the Holocene epoch. It was one of the last in a line of mammoth species, beginning with the African ...

that died about 17,100 years ago were found north of the Brooks Range. A research report on its movement range was published in 2021.Woolly mammoth walked far enough to circle Earth twice, study finds
theguardian.com 12 Aug 2021

Climate

While other Alaskan ranges to the south and closer to the coast can receive to of snow, the average snow precipitation on the Brooks Range is reported at to . Due to a changing climate, between the years 1969–2018 the Eastern and Western portions of the Brooks Range have experienced a 17.2% increase in annual precipitation.Thoman, R. & J. E. Walsh. (2019)
Alaska’s changing environment: documenting Alaska’s physical and biological changes through observations.
H. R. McFarland, Ed. International Arctic Research Center, University of Alaska Fairbanks. As measured at the Anaktuvuk Pass weather station (elevation ), the average summer temperatures are as a high and as a low. During the winter the average high is while the average low is .

Polar amplification Polar amplification is the phenomenon that any change in the net radiation balance (for example greenhouse intensification) tends to produce a larger change in temperature near the poles than in the planetary average. This is commonly referred to ...

is a force experienced in this region as global temperatures are rising. The northern and western regions of Alaska, where the Brooks Range lies, is experiencing a warming rate twice that of southeastern Alaska. The Brooks Range has experienced an increase in average summer temperature between 4.2 °F and 5.8 °F between the years 1969–2018. In certain areas of the Brooks Range, year round snow cover or "perennial snowfields", can be found. In 1985, 34 square miles of snowfields were recorded, where as that number has dropped to under four square miles in 2017.

Films

*2007 - ''Gates of the Arctic: Alaska's Brooks Range'' *2008 - ''Alone Across Alaska: 1,000 Miles of Wilderness'' *2011 - ''The Edge of the Earth'' (short film) *2014 - ''The World Beyond the World'' (short film)

Peaks

History

Ecology

Paleontology

Climate

Films

See also

Notes

Further reading