Colorado (redirected from Coloradan)

Colorado, state, United States

Colorado (kŏlərăd`ə, –răd`ō, –rä`dō), state, W central United States, one of the Rocky Mt. states. It is bordered by Wyoming (N), Nebraska (N, E), Kansas (E), Oklahoma and New Mexico (S), and Utah (W).

Facts and Figures

Area, 104,247 sq mi (270,000 sq km). Pop. (2000) 4,301,261, a 30.6% increase since the 1990 census. Capital and largest city, Denver. Statehood, Aug. 1, 1876 (38th state). Highest pt., Mt. Elbert, 14,433 ft (4,402 m); lowest pt., Arkansas River, 3,350 ft (1,022 m). Nickname, Centennial State. Motto, Nil Sine Numine [Nothing without Providence]. State bird, lark bunting. State flower, Rocky Mountain columbine. State tree, Colorado blue spruce. Abbr., Colo., CO

Geography

Colorado's eastern expanses are part of the High Plains section of the Great Plains. On their western edge the plains give way to the Rocky Mountains, which run north-south through central Colorado. The mountains are divided into several ranges that make up two generally parallel belts, with the Front Range and a portion of the Sangre de Cristo Mts. on the east and the Park Range, Sawatch Mts., and San Juan Mts. on the west. Mt. Elbert (14,433 ft/4,399 m) is the highest peak in the U.S. Rocky Mts. The mountain ranges are separated by high valleys and basins called parks. These include North Park, Middle Park, South Park, Estes Park, and San Luis Park. The Continental Divide runs north-south along the Rocky Mts. in Colorado.

One of the most scenic states in the country, Colorado has recreational parks including Rocky Mountain National Park, Black Canyon of the Gunnison National Park with its narrow gorge cut by the Gunnison River, Dinosaur National Monument in NW Colorado, and Great Sand Dunes National Monument and Preserve in S central Colorado. Mesa Verde National Park and Canyons of the Ancients National Monument, once home to the Anasazi cliff dwellers, are in the southwestern corner of the state, a beautiful but formidable area of mesas and canyons.

Most of W Colorado is occupied by the Colorado Plateau, where deep canyons have been formed by the action of the Colorado, Gunnison, and other rivers. Colorado has a mean elevation of c.6,800 ft (2,070 m) and has 51 of the 80 peaks in North America over 14,000 ft (4,267 m) high, thus laying claim to the name "top of the world."

A broad timber belt, largely coniferous and mostly within national forest reserves, covers large sections of the mountains. The mighty Colorado River originates in Rocky Mountain National Park, and the headwaters of the North Platte, South Platte, Arkansas, and Rio Grande also gather in Colorado's mountains. The average annual rainfall in Colorado is only 16.6 in. (42.2 cm), but the state has been able to develop otherwise unusable land and ranks high among the states in irrigated acres. The Colorado–Big Thompson project and the Fryingpan-Arkansas project are two major water-diversion systems that carry water by tunnel across the Continental Divide to farms on the plains of E Colorado.

Most of the population lives in cities among the Front Range foothills, principally in Denver, the capital, largest city, and regional metropolis. Other major cities are Colorado Springs, Aurora, Lakewood, and Pueblo.

Economy

Agriculture, especially the raising of cattle and sheep and production of dairy goods, is economically important in the state. Crops include wheat, hay, corn, and sugar beets. Since the 1950s manufacturing has been the major source of income in the state. Food processing is a major industry; others include the manufacture of computer equipment, aerospace products, transportation equipment, and electrical equipment; printing and publishing; and the production of fabricated metals, chemicals, and lumber. Federal facilities including army and air force bases, prisons, and the Denver Mint, as well as regional offices, contribute greatly to the economy. A new $4 billion international airport opened near Denver in Feb., 1995.

Tourism plays a vital role in Colorado's economy. The state's climate, scenery, historical sites, and extensive recreational facilities bring millions of visitors annually. Numerous resorts in towns such as Vail and Aspen attract visitors year-round as well as during ski season. Besides fine hunting, fishing, and skiing there are many special events held in the state, including arts festivals, rodeos, and fairs.

Gold, the lure to exploration and settlement of Colorado, was the first of many valuable minerals (notably silver and lead) discovered here. Leading minerals today are petroleum, coal, molybdenum, sand and gravel, and uranium. Gold is no longer mined extensively. There are also large coal and oil deposits.

Government, Politics, and Higher Education

Colorado's state government is based on the constitution drawn up in 1876 and since amended. The governor serves for a term of four years. The legislature is made up of a senate with 35 members and a house of representatives with 65 members. Colorado is represented in the U.S. Congress by two senators and six representatives and has eight votes in the electoral college. Democrat Roy Romer, elected governor in 1986 and reelected in 1990 and 1994, was succeeded by Republican Bill Owens, elected in 1998 and reelected in 2002. In 2006 a Democrat, Bill Ritter, won the governorship.

Among Colorado's institutions of higher learning are the Univ. of Colorado, at Boulder; the Univ. of Denver, at Denver; Colorado State Univ., at Fort Collins; and the United States Air Force Academy, at Colorado Springs.

History

Early Inhabitants, European Exploration, and U.S. Conquest

Colorado's earliest inhabitants were the Basket Makers, Native Americans who settled in the mesa country before the beginning of the Christian era. Later people known as cliff dwellers inhabited the area, building their pueblos in canyon walls.

The first European to enter the region was probably the Spanish conquistador Francisco Vásquez de Coronado in the 16th cent. Spain subsequently claimed (1706) the territory, although no Spanish settlements were established there. Part of the area was also claimed for France as part of the Louisiana Territory. At the end of the French and Indian Wars (1763), France secretly ceded the Louisiana Territory, including much of Colorado, to Spain. The French regained the whole area in 1800 by the secret Treaty of San Ildefonso concluded with Spain (see San Ildefonso, Treaty of).

The United States bought the area N of the Arkansas River and E of the Rocky Mts. in the Louisiana Purchase of 1803. The federal government sent expeditions to Colorado which generated some public interest in the new territory, and they explored routes opened earlier by the famous mountain men, trappers, and fur traders who included William H. Ashley, James Bridger, Jedediah S. Smith, Kit Carson, and the Bent brothers. Bent's Fort, in Colorado, was one of the best-known Western trading posts. Settlement in the area did not begin, however, until the United States acquired the remainder of present-day Colorado from Mexico by the Treaty of Guadalupe Hidalgo in 1848.

Gold, Settlement, and Statehood

In the early 1800s a small farming settlement had been established in the San Luis valley, but most settlers pushing westward across the Great Plains continued on to the more fertile lands of Oregon, Washington, and California. It was the discovery of gold that first brought large numbers of settlers to Colorado. Prospectors led by Green Russell discovered gold in 1858 at Cherry Creek, where part of the city of Denver now stands, and after another strike the following year, the mining boom began.

At the time of the gold rush the area in which the gold fields were located was part of the U.S. Kansas Territory. A group of miners organized the gold fields as Arapahoe co. of Kansas Territory. The region was divided into districts, and miners' and people's courts were set up to provide quick justice. The miners sought separate territorial status in 1859 and formed the illegal Territory of Jefferson, which operated until the bill for territorial status was passed by Congress in 1861. William Gilpin, the first territorial governor, chose the name Colorado [Span.,=red or colored]. Measures proposing statehood for Colorado were introduced in the U.S. Congress in 1864, and again in 1866 and 1867 when they were vetoed by Andrew Johnson. A bill granting Colorado's statehood was finally passed by Congress in 1876.

When the first settlers came to Colorado, the Ute lived in the mountain areas, while the Comanche, Cheyenne, Arapaho, and Kiowa inhabited the Great Plains. Warfare between plains and mountain ethnic groups was continuous. The tribes of the plains combined their forces in 1840 to halt the invasion of their homelands and hunting grounds by settlers, and violence ensued. The warfare finally culminated in the Native Americans' defeat after the Indian Wars (1861–69) and the Buffalo War (1873–74). Colorado's Native Americans now live mainly on the Southern Ute reservation and in the Denver area.

Decline and Diversification

While Colorado was seeking to establish a government and engaged in conflict with Native Americans, the state's mining boom was in sharp decline. The surface gold had been extracted in the middle 1860s, and mining areas became, and in many cases remain, studded with ghost towns—machinery abandoned and shacks deserted. Other towns, such as Central City with its famous opera house dating from the city's days of opulence, managed to stay alive.

The completion (1870) of a railroad link from Denver to the Union Pacific in Cheyenne, Wyo., and later railroad construction helped to stimulate the extension of farming and the growth of huge cattle ranches as well as to encourage an influx of settlers. Between 1870 and 1880 population increased almost fivefold. Denver briefly became the largest receiving market for sheep, and a smelting industry was established.

In the 1870s the discovery of silver-bearing lead carbonite ore at Leadville started a new mining boom. Prosperity was short-lived, however, for in the 1890s, despite a rich silver strike at Creede and the discovery of the state's richest gold field at Cripple Creek, Colorado suffered a depression. In 1893 the U.S. government stopped buying silver in order to restore confidence in the nation's currency, which had been placed on the gold standard in 1873. The silver market subsequently collapsed, dealing a severe blow to Colorado's economy.

Labor conflicts, disputes over railway franchises, and warfare between sheep and cattle interests also plagued the state at the turn of the century. Many of labor's battles in this period were fought in the mines of Colorado, and the lawlessness and ruthlessness that prevailed among both employers and miners were reminiscent of the early days of the mining camps. When the silver market broke, Colorado turned politically to fusion Populist-Democratic leaders advocating a return to bimetallism. The free-silver movement, however, was unsuccessful, and by 1910, with the improvement of national economic conditions, Colorado settled down to a predominantly agricultural economy.

The Twentieth Century

Large national parks, established in the early 1900s, have provided a continuing source of revenue; tourism has grown steadily. During World War I the price of silver soared again and the economy prospered. The stock-market crash of 1929 and the droughts of 1935 and 1937 brought hardships, but the economy recovered again during World War II, when the state's foods, minerals, and metal products were important to the war effort.

In the mid-1960s Colorado experienced a large influx of new residents and rapid urban growth and development, especially along a strip (c.150 mi/240 km long) centered on Denver and stretching from Fort Collins and Greeley in the north to Pueblo in the south. This growth, combined with the area's high altitude, caused pollution problems, most notably smog. The discovery and exploitation of oil created a boom in the 1970s, which collapsed in the early 1980s. Diversifying industry, swelling in-migration and accompanying construction, and tourism and recreation have since enabled Colorado to rebound, and between 1990 and 2000 it had the third largest percentage of growth of any state in the union.

Bibliography

See P. Eberhart, Guide to the Colorado Ghost Towns and Mining Camps (1959); C. Bancroft, Colorful Colorado: Its Dramatic History (1959); P. F. Dorset, The New Eldorado: The Story of Colorado's Gold and Silver Rushes (1970); L. R. Hafen, Colorado: The Story of a Western Commonwealth (1970); C. Abbott, Colorado: A History of the Centennial State (1982); M. Griffiths and L. Rubright, Colorado: A Geography (1983); G. Lawson, Colorado (1990).

---

Colorado, river, Argentina

Colorado (kōlōrä`thō), river, c.550 mi (885 km) long, rising from tributaries in the Andes and flowing SE across S central Argentina to the Atlantic Ocean. It marks the northern limit of Patagonia. It is also a rough boundary between the commercial agriculture to the north and ranching to the south. The Colorado's lower course splits into two branches that flow into the Atlantic Ocean; the river often overflows its banks in spring.

---

Colorado, river, United States

Colorado (1 kŏlərăd`ə, –răd`ō, –rä`dō 2 kŏlərā`də, –rä`də).

1 Great river of the SW United States, 1,450 mi (2,334 km) long, rising in the Rocky Mts. of N Colo., and flowing generally SW through Colo., Utah, Ariz., between Nev. and Ariz., and Ariz. and Calif., then into Mexico, emptying into the Gulf of California; drains c.244,000 sq mi (631,960 sq km). The Gunnison, Green, San Juan, and Little Colorado are the main tributaries in the upper basin of the Colorado; the Gila is the chief tributary of the lower basin. Silt deposited by the Colorado has formed a great delta across the northern part of the Gulf of California, cutting off the head of the gulf; the Salton Sea is a flooded remnant of the severed part. The mouth of the river was seen by Francisco de Ulloa in 1539; the lower part was explored by Hernando de Alarcón in 1540. The river flows through c.1,000 mi (1,610 km) of canyons, including Arizona's Grand Canyon; many national parks, monuments, and recreational areas lie along its banks. The Colorado's waters are used for power and irrigation, especially by means of the Colorado River storage project, the Colorado–Big Thompson project, Hoover Dam, Davis Dam, Imperial Dam, the All-American Canal, Parker Dam, and Glen Canyon Dam. Controversies over water rights on the Colorado have long raged between the United States and Mexico and among the bordering states (it supplies most of S California's water); treaties and compacts regulate the river's use. California and, to a lesser degree, Nevada have in the past drawn more water than they were designated to receive. A new compact in 2003 gave California 14 years to reduce its water usage to its legal limits. A greater problem, however, is that the 1922 Colorado River Compact that established the division of water use between the upper and lower basins was based on an estimate of the average annual flow that is 10% to 25% higher than long-term data suggest, due to the use of river gauge data from what is now known to be a relatively wet period in the river basin's history.

2 River, 894 mi (1,439 km) long, rising in the Llano Estacado, NW Tex., and flowing SE to Matagorda Bay, an inlet of the Gulf of Mexico; drains c.41,500 sq mi (107,485 sq km). Destructive floods, which prevented private development of the river for power, led the Texas legislature to set up the Lower, Central, and Upper Colorado River authorities to undertake projects for flood control, power plants, and irrigation. The Lower Colorado River Authority, with federal assistance, has been especially active, building five major dams (Buchanan, Roy Inks, Alvin J. Wirtz, Marble Falls, and Mansfield). These projects have benefited a large part of Texas, including the city of Austin. The scenic section of the river above Austin, which includes the lakes formed by the dams, is called Highland Lakes Country. The Central Colorado River Authority has constructed many small irrigation dams and also has jurisdiction over several city reservoirs. The Upper Colorado River Authority regulates the upper Colorado and the several branches of the Concho, a principal tributary.

---

Colorado

State (pop., 2000: 4,301,261), west-central U.S. Bordered by Wyoming, Nebraska, Kansas, Oklahoma, New Mexico, and Utah, it covers 104,100 sq mi (269,619 sq km); its capital is Denver. Lying astride the Rocky Mountains, the state has three physiographic regions: the plains, a semiarid segment of eastern Colorado; the Colorado Piedmont in the central part of the state, where most of the population lives; and the southern Rocky Mountains and mesas of western Colorado. Its large urban population has grown faster than the national average. Its original inhabitants were Plains and Great Basin Indians, including the Arapaho, Cheyenne, and Ute. The area was claimed by Spain in 1706 but later passed in large part to France. Eastern Colorado was part of the Louisiana Purchase in 1803; the remainder stayed in Spanish and, after independence, Mexican hands until 1848. Gold was discovered in 1859 and touched off a population boom. Organized as the territory of Colorado in 1861, it achieved U.S. statehood in 1876. Agriculture, cattle production, and mining, as well as manufacturing, are important to the economy. Government military installations and service industries have become prominent, and tourism is a major source of the state's income (see Aspen; Boulder; Vail).

---

Colorado

Group of Indian people of Ecuador's Pacific coast. In the tropical lowlands where the Colorado traditionally have lived, they and the neighbouring Cayapas are the last remaining aboriginal groups. The Colorado (Spanish: “red”), so named because of their use of red pigment to decorate their faces and bodies, have been fishermen, hunters, and shifting cultivators; some, however, have taken up work on plantations, and others have migrated to work in the city.

---

Colorado

1. a state of the central US: consists of the Great Plains in the east and the Rockies in the west; drained chiefly by the Colorado, Arkansas, South Platte, and Rio Grande Rivers. Capital: Denver. Pop.: 4 550 688 (2003 est.). Area: 269 998 sq. km (104 247 sq. miles)

2. a river in SW North America, rising in the Rocky Mountains and flowing southwest to the Gulf of California: famous for the 1600 km (1000 miles) of canyons along its course. Length: about 2320 km (1440 miles)

3. a river in central Texas, flowing southeast to the Gulf of Mexico. Length: about 1450 km (900 miles)

4. a river in central Argentina, flowing southeast to the Atlantic. Length: about 850 km (530 miles)

---

Colorado State Information

Phone: (303) 866-5000
www.colorado.gov


Area (sq mi): 104093.57 (land 103717.53; water 376.04). Pop per sq mi: 45.00.
Pop 2005: 4,665,177. State rank: 0. Pop change: 2000-20005 8.50%; 1990-2000 30.60%. Pop 2000: 4,301,261 (White 74.50%; Black or African American 3.80%; Hispanic or Latino 17.10%; Asian 2.20%; Other 11.10%). Foreign born: 8.60%. Median age: 34.30.
Income 2000: per capita $24,049; median household $47,203; Pop below poverty level: 9.30%. *Personal per capita income 2000-2003: $33,370-$34,561.
Unemployment 2004: 5.60%. Change from 2000: 2.90%. Median travel time to work: 24.30 minutes. Working outside county of residence: 33.00%.

---

List of Colorado counties:

Adams County Alamosa County Arapahoe County Archuleta County Baca County Bent County Boulder County Broomfield City & County Chaffee County Cheyenne County Clear Creek County Conejos County Costilla County Crowley County Custer County Delta County Denver City & County Dolores County Douglas County Eagle County El Paso County Elbert County

Fremont County Garfield County Gilpin County Grand County Gunnison County Hinsdale County Huerfano County Jackson County Jefferson County Kiowa County Kit Carson County La Plata County Lake County Larimer County Las Animas County Lincoln County Logan County Mesa County Mineral County Moffat County Montezuma County Montrose County

Morgan County Otero County Ouray County Park County Phillips County Pitkin County Prowers County Pueblo County Rio Blanco County Rio Grande County Routt County Saguache County San Juan County San Miguel County Sedgwick County Summit County Teller County Washington County Weld County Yuma County

---

Colorado Parks

• US National Parks

  Bent's Old Fort National Historic Site Black Canyon of the Gunnison National Park Colorado National Monument Curecanti National Recreation Area

  Dinosaur National Monument Florissant Fossil Beds National Monument Great Sand Dunes National Park & Preserve Hovenweep National Monument

  Mesa Verde National Park Rocky Mountain National Park Sand Creek Massacre National Historic Site Yucca House National Monument

• Urban Parks

  City Park Garden of the Gods Park

  North Cheyenne Cañon Park Palmer Park

  Red Rock Canyon Open Space Washington Park

• State Parks

  Arkansas Headwaters Recreation Area Barr Lake State Park Bonny Lake State Park Boyd Lake State Park Castlewood Canyon State Park Chatfield State Park Cherry Creek State Park Cheyenne Mountain State Park Crawford State Park Eldorado Canyon State Park Eleven Mile State Park Golden Gate Canyon State Park Harvey Gap State Park Highline Lake State Park

  Jackson Lake State Park James M. Robb - Colorado River State Park John Martin Reservoir State Park Lake Pueblo State Park Lathrop State Park Lory State Park Mancos State Park Mueller State Park Navajo State Park North Sterling State Park Paonia State Park Pearl Lake State Park Ridgway State Park Rifle Falls State Park

  Rifle Gap State Park Roxborough State Park Saint Vrain State Park San Luis State Park & Wildlife Area Spinney Mountain State Park Stagecoach State Park State Forest State Park Steamboat Lake State Park Sweitzer Lake State Park Sylvan Lake State Park Trinidad Lake State Park Vega State Park Yampa River State Park

• Parks and Conservation-Related Organizations - US

  Access Fund Colorado Environmental Coalition Colorado Wildlife Federation

  Good Sam Recreational Vehicle Club International Mountain Bicycling Association (IMBA) Leave No Trace Center for Outdoor Ethics Inc

  Mission: Wolf Native American Rights Fund (NARF) Thorne Ecological Institute

• National Wildlife Refuges

  Alamosa National Wildlife Refuge Arapaho National Wildlife Refuge Browns Park National Wildlife Refuge

  Hutton Lake National Wildlife Refuge Monte Vista National Wildlife Refuge Pathfinder National Wildlife Refuge

  Rocky Mountain Arsenal National Wildlife Refuge Two Ponds National Wildlife Refuge

• National Trails

  Continental Divide National Scenic Trail

  Continental Divide National Scenic Trail

• National Scenic Byways

  Colorado River Headwaters Byway Dinosaur Diamond Prehistoric Highway - Colorado Frontier Pathways Scenic and Historic Byway Gold Belt Tour Scenic and Historic Byway

  Grand Mesa Scenic and Historic Byway San Juan Skyway Santa Fe Trail - Colorado Top of the Rockies Scenic and Historic Byway

  Trail of the Ancients - Colorado Trail Ridge Road/Beaver Meadow Road

• National Heritage Areas

  Cache La Poudre River Corridor

• National Grasslands

  Comanche National Grassland

  Pawnee National Grassland

• National Forests

  Arapaho & Roosevelt National Forests Grand Mesa, Uncompahgre & Gunnison National Forests

  Pike & San Isabel National Forests Rio Grande National Forest

  San Juan National Forest White River National Forest

---

Colorado

Thirty-eighth state; admitted on August 1, 1876

State capital: Denver

Nickname: Centennial State

State motto: Nil sine Numine (Latin “Nothing without the Diety”)

State animal: Rocky Mountain bighorn sheep (Ovis canadensis)

State bird: Lark bunting (Calamospiza melanocoryus Stejneger)

State fish: Greenback cutthroat trout (Oncorhynchus clarki somias)

State flower: Columbine (Aguilegia caerules)

State folk dance: Square dance

State fossil: Stegosaurus

State gem: Aquamarine

State grass: Blue Grama

State insect: Colorado Hairstreak Butterfly (Hypaurotis cysalus)

State mineral: Rhodochrosite

State rock: Yule marble

State song: “Where the Columbines Grow” and “Rocky Mountain High”

State tartan: Colorado State Tartan

State tree: Colorado blue spruce (Picea pungens)

More about state symbols at:

www.colorado.gov/dpa/doit/archives/history/symbemb. htm

SOURCES:

AmerBkDays-2000, p. 555 AnnivHol-2000, p. 128 DictDays-1988, p. 22

STATE OFFICES:

State web site: www.colorado.gov

Office of the Governor 136 State Capitol Bldg Denver, CO 80203 303-866-2471

fax: 303-866-2003
www.colorado.gov/governor

Secretary of State
1700 Broadway
2nd Fl
Denver, CO 80290
303-894-2200
fax: 303-894-4860
www.sos.state.co.us

Colorado State Library
201 E Colfax Ave
Rm 309
Denver, CO 80203
303-866-6900
fax: 303-866-6940
www.cde.state.co.us/index_library.htm

---

Colorado 

a state in the western USA. Area, 270,000 sq km. Population, 2.2 million (1970); urban population, 78.5 percent. Capital and largest city, Denver.

The state’s territory is crossed in its central part from north to south by the Rocky Mountains (Mount Elbert, 4,399 m). Located in the east are the Great Plains and in the west, the Colorado Plateau. The climate is moderate and continental. The average January temperature in the plains and the plateau ranges from 0° to 4°C and in July, from 20° to 22°C. Annual precipitation amounts to 300–400 mm. The principal rivers are the South Platte, Arkansas, Rio Grande, and Colorado. Vegetation in the east is of the steppe type, and in the west it is semidesert. The mountain slopes are covered, for the most part, by coniferous forests.

Colorado is an industrial-agrarian state. In 1969 the mining industry included 13,000 employees and the processing industry, 114,000. Ores of rare and nonferrous metals are mined, as well as uranium, gold, petroleum, and coal; Colorado is in first place in the USA in the mining of molybdenum (the deposit at Climax). There is a food-processing industry (meat canning, sugar, and flour); ferrous (Pueblo) and nonferrous metallurgy are developed, as well as the metalworking, chemical, and rubber industries. The state has diverse machine-building industries (the production of mining and road-building equipment, radio elecironies, and space rockets); the chief center is Denver (with more than three-fourths of the employees in Colorado’s processing industry).

The foremost branch of agriculture is livestock raising for meat (for the most part, younger animals); in 1970 the state had 3.3 million head of cattle, including 100,000 milch cows; 300,000 pigs; and 1.2 million sheep. Sown on the irrigated lands in the river valleys are sugar beets, potatoes, and fodder grasses (especially various types of alfalfa). On the Great Plains the principal crop is wheat. Large commercial farms predominate.

V. M. GOKHMAN

---

Colorado 

a river primarily in the USA, with its lower course in Mexico. Length, 2,740 km (with its right tributary, Green River, 3,200 km); basin area, 635,000 sq km.

The river rises in the forerange of the Rocky Mountains and flows into the Gulf of California in the Pacific Ocean, forming a delta with an area of 8,600 sq km. It flows primarily through the semidesert and desert regions of Utah and Arizona. It cuts through the Colorado Plateau and forms deep canyons with a total length of approximately 800 km, including one of the largest in the world—the Grand Canyon. The major left tributaries are the San Juan, Little Colorado, and Gila. The river is fed by snows from the Rocky Mountains. High flows of water begin in April and end in July; during the autumn and winter low flows occur.

The average discharge of water at Lees Ferry (the middle course) is 508 cu m per sec; at its mouth the discharge is only 5 cu m per sec as a result of the almost complete diversion of water by canals and aqueducts for irrigation and for supplying the cities on the California coast of the USA (including Los Angeles) with water. For this purpose the Glen Canyon Dam was built (at a point below the juncture of the San Juan) as well as the Hoover Dam (Boulder Dam), which form, respectively, the major reservoirs of Lake Powell and Lake Mead (each with an area of about 650 sq km and a volume of more than 34 cu km); also among those constructed are the Davis and Parker dams with the smaller Mojave and Havasu reservoirs (all these dams have hydroelectric power plants), as well as the Palo Verde, Imperial, and Morelos water-diversion canals. There are large reservoirs and irrigation systems in the Gila River basin (the Roosevelt, Santa Clara, Horseshoe and other reservoirs). The Colorado carries along a great deal of sediment (an average of 160 million tons annually), which is almost all deposited in the Powell and Mead reservoirs. In its lower reaches the Colorado is navigable for riverboats, but for transportation it is insignificant.

REFERENCES

Freeman, L. R. The Colorado River. London, 1923.
Powell, J. W. Exploration of the Colorado River. New York, 1961.

O. A. SPENGLER

---

Colorado 

a river in the southern part of the USA, located in the state of Texas. Length, 1,450 km; basin area, 107,000 sq km.

The river rises in the plateau of the Llano Estacado, and it flows into the Gulf of Mexico. In the spring there are floods and in the summer, freshets. The average discharge of water is 81 cu m per sec. There are many reservoirs, which are used for irrigation. The city of Austin is situated on the Colorado River.

---

Colorado 

a river in Argentina, in northern Patagonia. The Colorado measures more than 1,200 km long and drains an area of approximately 350,000 sq km. Formed by the confluence of the Grande and Barrancas rivers, which originate on the eastern slopes of the Andes, it crosses the dry region of northern Patagonia in a deep, wide valley and empties into Bahía Blanca of the Atlantic Ocean, forming a delta. There are flash floods, mainly in the spring. The mean flow rate is 140 cu m per sec. The Colorado is navigable for a distance of 320 km from the mouth.