COLORADO, a State in the Western Division of the North American Union; bounded by Wyoming, Nebraska, Kan sas, Oklahoma, New Mexico, and Utah; gross area, 103,645 square miles; ad mitted to the Union, July 4, 1876; num ber of counties, sixty-three; population (1890) 412,198; (1900) 539,700; (1910) 799,024; (1920) 939,629; capital, Denver.
Topography.—Colorado is very moun tainous, being traversed by the Rocky Mountains, which extend over nearly the entire W. part of the State. The aver age altitude of the State is 7,000 feet, the lowest portion being 3,000 feet above the sea, and there are over 100 moun tain peaks more than 13,000 feet high. The Sawatch or Saguache range, or Great Divide, is a continuation of the Sierra Madre range of Mexico, and con tains the peaks, Mt. Harvard, 14,375; Mt. Elbert, 14,351; and the Mountain of the Holy Cross, 14,175 feet. The Park Range joins this range in the N., highest points Torrey's Peak, 14,147 feet, and Gray's Peak, 14,341 feet. The Front Range contains Pike's Peak, 14,147 feet, and Evans, 14,330 feet, and is sit uated a little E. of the main ranges. In the S. is the Sangre de Cristo range, con taining Blanca Peak, the highest in the State, 14,464 feet. In the W. part are several lower ranges, running in a gen eral N. W. and S. E. direction. The val leys are a distinguishing feature of the scenery, and are known as parks. San Luis is the largest and has an area of 8,000 square miles, quite level, and at an elevation of 7,000 feet. The only lake of any size in Colorado is in this park, is about 6 miles in length, and is fed by nearly 20 streams. Colorado is the principal watershed in the Western States, many of the largest rivers having their origin here, among them the Platte, Colorado, San Miguel, Arkansas, and Rio Grande del Norte. Nearly all these rivers wind their way through rocky cafions, varying from one to 3,000 feet in depth. "Monument Park" and the "Garden of the Gods" have rock spires, rising above the meadow land, shaped like towers and pillars, caused by erosion.
Geology.—The mountains of Colorado are mostly of azoic and eozoic formation, while the E. and S. W. slopes are of palieozoic, bordered by metalliferous, jurassic, and triassic strata in the W. central parts. The extreme E. plain is
largely tertiary, and the S. W. is chiefly cretaceous, the valleys of the South Platte and Arkansas rivers being of this formation.
Soil, Climate, etc.—Colorado has about 15,000 square miles of fertile arable land, and about 70,000 square miles of grazing land. Most of the land will pro duce abundant crops under irrigation, which is now being carried on exten sively, one irrigating canal having a length of 54 miles. The mountains are well covered with pine, spruce, and fir forests. The climate is very healthful and mild, and people suffering from pul monary and asthmatic troubles find much relief here. There are various mineral springs, which are valuable for medicinal purposes. The hot sulphur springs in Middle Park and Wagon Wheel gap, and the hot, iron, and soda springs in Mani tou are popular resorts.
Mineral Production.—Colorado for many years was first among the States in the value of its mineral products. For various reasons, including the develop ment of mineral fields in other Western States, the working out of hitherto im portant mines, and the decline in the price of silver, have resulted in a rela tive change of this position. The min eral industry, however, is still the most important in the State, and Colorado continues to rank high among the min eral-producing States. The total value of the mineral products in 1917, the latest date for which complete figures are available, was $80,586,021. Coal was the most valuable of the mineral prod ucts, with 12,483,336 tons, valued at $27, 669,129. Gold was second in value with 760,901 fine ounces, valued at $15,729, 224. Zinc was third with 60,158 tons, valued at $12,272,209. The silver pro duction was 7,304,353 fine ounces, valued at $6,018,787. Other important mineral products were coke, clay products, tungsten ore, and ferro alloys. The pro duction of the principal minerals mined in the State in 1919 was as follows: Gold, $9,892,000; silver, 5,630,000 ounces; lead, 35,650,000 pounds; copper, 3,400,000 pounds; zinc, 52,300,000 pounds. The total value of these products was 522,000. The estimated coal production in 1919 was 10,100,000 short tons, a de crease of over 2,000,000 tons from the production of 1918.