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Rocky Mountains Essay Research Paper Rocky Mountains (стр. 1 из 3)

Rocky Mountains Essay, Research Paper

Rocky Mountains or Rockies, great chain of rugged mountain ranges in western

North America, extending from central New Mexico to northeastern British

Columbia, a distance of about 3220 km (about 2000 mi). The Great Basin and the

Rocky Mountain Trench, a valley running from northwestern Montana to northern

British Columbia, border the Rockies on the east by the Great Plains and on the

west. The Rocky Mountains form part of the Great, or Continental, Divide, which

separates rivers draining into the Atlantic or Arctic oceans from those flowing

toward the Pacific Ocean. The Arkansas, Colorado, Columbia, Missouri, Rio

Grande, Saskatchewan, and Snake rivers rise in the Rockies. The Rockies may be

divided into four principal sections?Southern, Central, Northern, and

Canadian. The Southern Rockies, which include the system’s broadest and highest

regions, extend from central New Mexico, through Colorado, to the Great Divide,

or Wyoming, Basin, in southern Wyoming. This section, which encompasses Rocky

Mountain National Park, is composed chiefly of two northern-southern belts of

mountain ranges with several basins, or parks, between the belts. The component

parts include the Sanger de Crisco and Laramie mountains and the Front Range, in

the east, and the San Juan Mountains and the Swatch and Park ranges, in the

west. The Southern Rockies include the chain’s loftiest point, Mount Elbert

(4399 m/14,433 ft high), in central Colorado. More than 50 other peaks of the

Rockies rising above 4267 m (14,000 ft) are in Colorado; these include Longs

Peak (4345 m/14,255 ft high) and Pikes Peak (4301 m/14,110 ft high). The Central

Rockies are in northeastern Utah, western Wyoming, eastern Idaho, and southern

Montana. They encompass the Bighorn; Bear tooth, and Unite Mountains and the

Absaroka, Wind River, Salt River, Teton, Snake River, and Wasatch ranges. The

Unite Mountains are the only major portion of the Rockies that extends east west

rather than north south. Among the peaks of the Central Rockies, which include

Grand Eton and Yellowstone national parks, are Gannett Peak (4207 m/13,804 ft

high), Grand Eton (4197 m/13,771 ft high), and Fremont Peak (4185 m/13,730 ft

high). The Northern Rockies are in northern Idaho, western Montana, and

northeastern Washington. They include the Saw tooth, Cabinet, Salmon River, and

Clearwater Mountains and the Bitterroot Range. The loftiest points in the

section, which includes Glacier National Park, are Granite Peak (3901 m/12,799

ft high) and Borax Peak (3859 m/12,662 ft high). The Canadian Rockies, located

in southwestern Alberta and eastern British Columbia, are composed of a

relatively narrow belt of mountain ranges that terminates at the Lizard River

lowland in northeastern British Columbia. The peaks of the section, which takes

in Banff, Jasper, Kootenay, Waterton Lakes, and Yoho National Parks, include

Mount Robson (3954 m/12,972 ft high), Mount Columbia (3747 m/12,294 ft high),

and The Twins (3734 m/12,251 ft high). Slopes generally are very steep, and

there are numerous glaciers. The Rocky Mountains are a geologically complex

system with jagged peaks as well as almost flat-topped elevations. The Rockies

were formed mainly by crustal uplifts in comparatively recent times, during the

late Cretaceous and early Tertiary periods, and later were reshaped by

glaciation during the Pleistocene Epoch. Today the Rockies receive moderate

amounts of precipitation, most of which occurs in the winter. Lower levels are

covered chiefly by grassland, which gives way to extensive forests, principally

of conifers. Above the woodland is a zone of grasses and scattered shrubs. Most

peaks have little vegetation around the summit, and some have a year-round cap

of snow and ice. The Rockies are sparsely populated for the most part and

contain few cities. The principal economic resources of the mountains are

minerals, such as coal, copper, gold, iron ore, lead, molybdenum, petroleum and

natural gas, silver, and zinc. Important mining centers include Leadville and

Climax, Colorado; Atlantic City, Wyoming; Kellogg, Idaho; Butte, Montana; and

Fernie and Kimberley, British Columbia. Major forest products industries,

especially lumbering, are concentrated in the Northern and Canadian Rockies, and

large numbers of sheep and cattle are raised in the Rockies of Colorado,

Wyoming, and Montana. The chain has many centers for outdoor recreation and

tourism. Bighorn Mountains, isolated range of the Rocky Mountains, lying east of

the Bighorn River and extending generally north from central Wyoming into

southern Montana. The range averages more than 2134 m (7000 ft) in elevation;

the highest summit is Cloud Peak (4019 m/13,187 ft) in Wyoming. Along the upper

levels are large coniferous forests, which are part of Bighorn National Forest.

Bitterroot Range, mountain range, northwestern United States, a chain of the

Rocky Mountains, extending about 700 km (about 435 mi) along the Montana-Idaho

border. Rugged and forested, with an average elevation of 2740 m (about 9000

ft), it remains one of the most inaccessible areas in the United States. In 1805

the Lewis and Clark Expedition traveled west through Lolo Pass (1595 m/5233 ft)

in the range. Guadalupe Mountains, mountain range, southwestern United States, a

branch of the Rocky Mountains, extending from southern New Mexico to western

Texas. Guadalupe Peak (2667 m/8749 ft above sea level), the highest in the

chain, is in Texas. Laramie Mountains, range of the Rocky Mountains, western

United States, extending from southeastern Wyoming into northern Colorado. The

highest point, Laramie Peak, is 3131 m (10,272 ft) above sea level. Coal, the

principal mineral, is found in the foothills. San Juan Mountains, mountain

range, southwestern United States, in southwestern Colorado and northwestern New

Mexico. Part of the Rocky Mountains, it is of volcanic origin and is rich in

minerals. The highest peaks are in Colorado and include Uncompahgre Peak (4361

m/14,309 ft), Mount Sneffels (4313 m/14,150 ft), and Wetterhorn Peak (4272

m/14,017 ft). Sangre de Cristo Mountains, mountain range, western United States,

the southernmost range of the Rocky Mountains, in south central Colorado and

north central New Mexico. The very high and narrow range extends southeast and

south for about 354 km (220 mi), from Salida, Colorado, to Santa Fe County, New

Mexico. Blanca Peak (4372 m/14,345 ft), in Colorado, is one of the highest

mountains of the Rockies. Sawatch Range, mountain range, central Colorado, a

branch of the Rocky Mountains. The range extends for about 177 km (about 110 mi)

and reaches a height of 4399 m (14,433 ft) at Mount Elbert, the highest point in

the state. Teton (mountain range), range of the Rocky Mountains, in northwestern

Wyoming, and southwestern Idaho, just south of Yellowstone National Park, west

of Jackson Lake and the Snake River. The highest peak is Grand Teton (4197

m/13,771 ft), located in Grand Teton National Park. Teton Pass (2569 m/8429 ft)

and Phillips Pass (3261 m/10,700 ft) are just south of the park. Uinta

Mountains, mountain range, western United States, mainly in northeastern Utah

and partly in southwestern Wyoming, part of the Rocky Mountains. The peaks of

the Uinta Mountains are mostly flat because of erosion by glaciers and the

waters of the Yampa and Green rivers. The range is about 240 km (about 150 mi)

long and 48 to 64 km (30 to 40 mi) wide. The highest elevation is Kings Peak,

which is 4123 m (13,528 ft) high and is also the highest point in Utah. Wasatch

Range, mountain range, western United States, in the Rocky Mountain system. The

range is about 240 km (about 150 mi) long; part of the Central Rockies, it

begins in southeastern Idaho and runs southward, east of the Great Salt Lake and

through the center of Utah, gradually ending in southwestern Utah. The average

height of the range is about 3050 m (about 10,000 ft), and the highest peak,

Mount Nebo, is 3620 m (11,877 ft) high. Wind River Range, range of the Rocky

Mountains, western Wyoming, forming part of the Continental Divide. The Green

River rises in the southwestern slope of the range, and many tributaries of the

Wind River flow off on the northeastern side. The range contains Fremont Peak

(4185 m/13,730 ft) and Gannett Peak (4207 m/13,804 ft); the latter is the

highest point in Wyoming. Arkansas (river, United States), river, western U.S.,

a major tributary of the Mississippi River, 2350 km (1460 mi) long. Rising in

central Colorado, in the Sawatch Range of the Rocky Mountains, at an altitude of

about 4270 m (about 14,000 ft), the river flows generally east and forms a

turbulent stream passing over rocky beds and through deep canyons such as the

Royal Gorge. As it flows through the plains of Kansas, the river broadens to a

wider, less turgid stream until it enters Oklahoma; at that point it receives

two chief tributaries, the Cimarron and the Canadian rivers. Except for a large

northern bend in Kansas, the Arkansas River follows a southeastern course,

merging with the Mississippi River above Arkansas City, Arkansas. The water

levels of the river are extremely variable, and several dams have been built for

flood control and irrigation and to create hydroelectric power; one of the most

impressive, the John Martin Dam in southeastern Colorado, was built in 1948. The

Arkansas River Navigation System, completed in the early 1970s, made the river

navigable to Tulsa, Oklahoma. Athabasca, river and lake, in western Canada, that

form part of the Mackenzie River system. The Athabasca River, 1231 km (765 mi)

long, begins in Jasper National Park in southwestern Alberta. Its source is the

Columbia Icefield, high in the Rocky Mountains. The river flows northeast across

Alberta and empties through a shallow delta into Lake Athabasca in northeastern

Alberta. The river was once an important route for fur traders. Lake Athabasca,

which straddles the AlbertaSaskatchewan- border, is about 320 km (about 200 mi)

long and covers about 7936 sq km (about 3064 sq mi). Fort Chipewyan, which was

built along the southwestern shore of the lake in 1788, became one of the

region’s most important fur-trading posts. Today Lake Athabasca is used for

commercial fishing. It is drained to the north by the Slave River. Large

deposits of petroleum-bearing sand are located along the lower Athabasca River,

near Fort McMurray. Long known but untapped because of high extraction costs,

the deposits are now mined using new technology and efficient methods. In 1994

the output amounted to one-quarter of Canada’s crude oil production. Canadian,

also South Canadian, unnavigable river, southwestern United States, 1460 km (906

mi) long. The Canadian River is formed in northeastern New Mexico by the union

of several branches from the southern Rocky Mountains. The river flows south

through New Mexico and then turns east, crossing the Texas Panhandle into

Oklahoma. Following a meandering course, it finally joins the Arkansas River.

The river’s only major tributary is the North Canadian River, 1260 km (784 mi)

long, which runs almost parallel to the Canadian River in Oklahoma. The

tributary joins the Canadian River at Eufaula in eastern Oklahoma to form the

Eufaula Reservoir. In northeastern New Mexico, a semiarid region, the Canadian

River provides an important water source at the Conchas Dam, a flood-control and

irrigation project. Colorado (river, North America), river, in southwestern

United States and northwestern Mexico, 2330 km (1450 mi) long, the longest river

west of the Rocky Mountains. The Colorado rises just west of the Continental

Divide, in northern Colorado, and, for the first 1600 km (about 1000 mi) of its

course, passes through a series of deep gorges and canyons that were created by

the eroding force of its current. The river flows in a generally southwestern

direction across Colorado into southeastern Utah, where it joins its chief

tributary, the Green River. After crossing the northern portion of Arizona, the

Colorado flows west for 446 km (277 mi) through the majestic Grand Canyon. It

then flows in a generally southerly direction and forms the boundary between

Arizona and the states of Nevada and California. Near Yuma, Arizona, the river

crosses the international border into Mexico and flows for about 145 km (90 mi)

to its mouth on the Gulf of California, an inlet of the Pacific Ocean. Besides

the Green River, the most important tributaries of the Colorado include the

Dolores and Gunnison rivers, in Colorado; the San Juan River, in Utah; and the

Little Colorado and Gila rivers, in Arizona. With its tributaries, the Colorado

drains portions of seven states, a total area, in Colorado, Wyoming, Nevada,

Utah, Arizona, New Mexico, and California, of about 626,800 sq km (about 242,000

sq mi) and 5180 sq km (2000 sq mi) more in Mexico. To control the tremendous

flow of the Colorado, particularly under flood conditions, an extensive series

of dams, many of them constructed by the U.S. Bureau of Reclamation, has been

built along the river and its tributaries. Notable is the Hoover Dam, which

impounds the river at the Black Canyon to form Lake Mead, one of the largest

artificial lakes in the world. The Glen Canyon Dam, in north-central Arizona

just south of the Utah border, is the third highest dam in the U.S. In addition

to regulating the flow of water, dams on the Colorado harness hydroelectric

power and provide storage reservoirs for irrigation projects. As such, they have

been instrumental in reclaiming the semiarid and arid regions through which the

river flows. The Imperial Valley of southern California is an excellent example

of land reclaimed by the waters of the Colorado. A number of reservoirs have

been incorporated into national recreation areas. The Glen Canyon National

Recreation Area in Utah encompasses Lake Powell, formed by the Glen Canyon Dam.

Lakes Mead and Mohave (the latter formed by Davis Dam) are part of Lake Mead

National Recreation Area in Arizona. The Colorado was first explored by the

Spanish navigator Hernando de Alarc?n, who ascended the river for more than 160

km (100 mi) in 1540-1541. The Colorado and its chief tributary, the Green, were

thoroughly explored for the first time in 1869 by the American geologist John

Wesley Powell. On this survey Powell and his party made the first recorded

passage of the Grand Canyon. The construction of the Glen Canyon Dam in 1963

dramatically reduced the natural flow of sand and nutrients down the Colorado

River and into the Grand Canyon. In March 1996 the federal government released

more than 380 billion liters (100 billion gallons) of water from Glen Canyon

Dam. This artificial flood added more than three feet to some beaches downstream

and cleared fish spawning grounds of debris and sediment. Further Reading

Columbia (river, North America), Major River of western North America, rising in

Columbia Lake, just west of the main range of the Rocky Mountains, in

southeastern British Columbia. The river was formerly known as the Oregon River.

The Columbia River is about 2000 km (1240 mi) long. It initially flows

northwest, through a long, narrow valley called the Rocky Mountain Trench, and

then turns sharply south, skirting the Selkirk Mountains and passing through

Upper Arrow Lake and Lower Arrow Lake. It next receives the Kootenay (spelled

Kootenai in the United States) and Pend Oreille rivers before entering the state

of Washington, where it first flows south and then traverses a great arc, known

as the Big Bend. After receiving the Snake River, the Columbia turns west and

forms much of the boundary between the states of Washington and Oregon before

emptying into the Pacific Ocean through a broad estuary. The river flows through

several spectacular canyons and deep valleys. About one-third of its course is

in Canada. The Columbia and its tributaries together drain a vast basin of about

673,400 sq km (about 260,000 sq mi). Large oceangoing ships can navigate the

lower Columbia River as far as Vancouver, Washington; and, with the aid of

locks, smaller marine vessels can reach The Dalles, Oregon, about 300 km (about

186 mi) upstream. Barges and other shallow-draft boats can navigate a further

220 km (137 mi). The Columbia River has immense hydroelectric potential, and

since the 1930s several large power projects have been built on it. The largest

of these, the Grand Coulee Dam, in central Washington, is the key unit of the

Columbia Basin Project, a federal undertaking also designed to irrigate up to