tory, etc. A municipal heating plant is in successful operation. Population, in 1890, 1563; in 1900, 1967.
IDAHO, ī′dȧ-hō (North American Indian, gem of the mountains). One of the Western States of the American Union, lying between latitudes 42° and 49° N., and longitudes 111° and 117° W. It is bounded on the north by British Columbia, on the east by Montana and Wyoming, on the south by Utah and Nevada, and on the west by Oregon and Washington. The extreme length from north to south along the western boundary is 485 miles. The width varies from about 50 miles in the north to nearly 300 miles in the south. Its area is 84,800 square miles, including 510 square miles covered by lakes.
Topography. The surface of Idaho is elevated and mostly mountainous. Lying between the main axis of the Rocky Mountains on the east and the Cascades on the west, the State embraces a portion of the Great Basin, a plateau lying 2000 to 5000 feet above the sea, while the northern and eastern parts are traversed by mountain ranges whose loftier summits rise above the snow-line. The principal ranges, the Salmon River and Bitter Root, attain their maximum development near the eastern border, but they send out spurs which extend nearly across the whole width of the State. Northward from the Bitter Root Mountains the system of elevations is continued by the Cœur d'Alêne and Cabinet ranges to the Canadian frontier. In the extreme southeast are the Bear, Blackfoot, and Snake River ranges, offshoots from the main Rocky Mountain system in Wyoming. Nearly the whole area of Idaho is drained into the Columbia by the Kootenai, Clark Fork, Spokane, and Snake rivers. The Snake, or Lewis Fork, is much the largest, its basin within the State covering more than 60,000 square miles, and its course being about 850 miles. It receives important tributaries in the Boise, Payette, Weiser, Owyhee, Salmon, and Clearwater, but its waters are usually shallow. In its course from east to west it passes over three falls, the American, the Shoshone, and the Salmon. The Shoshone Falls have a perpendicular descent of nearly 200 feet. Below the Salmon Falls the river is navigable for light-draught boats to the mouth of the Powder River. In the northern part of the State there are several lake basins, including Pend Oreille, Kaniksu, and Cœur d'Alêne, and in the southeast on the Utah boundary. Bear Lake drains through the Bear River into Great Salt Lake.
Climate and Soil. The climate in the more elevated parts is severe, with heavy snowfall in winter; the plains and valleys have a milder climate, free from great extremes, as the summer heat is moderated by mountain breezes. The rainfall in the south is very light, increasing toward the north and east, where the elevated ranges arrest the moist winds. Agriculture is thus limited to the mountain valleys and to the basins of the large rivers, such as the Salmon, Clearwater, Payette, and Boise, where irrigation can be practiced. These basins have a rich alluvial soil that produces excellent crops of cereals and fruits. The uplands have a moderately fertile soil of sands and clays, and are best adapted to grazing.
Flora and Fauna. See paragraphs on these respective topics under Rocky Mountains and United States.
Geology and Mineral Resources. Geologically Idaho exhibits the general features characteristic of the Rocky Mountain States. Strata of Paleozoic, Mesozoic, and later ages alternate with eruptive and metamorphic rocks. Along the Snake River there is a vast lava-bed forming a desert nearly 400 miles long and 40 to 60 miles wide, the eastern end of a volcanic belt that extends to the Pacific. The fissures from which the molten rock poured out during the late Tertiary period are generally concealed beneath the thick sheets, although their position may be indicated by the lines of flow. The surface of this region is a level plain, almost destitute of vegetation.
Mining. The mineral resources of the State, including deposits of gold, silver, lead, iron, coal, and salt, are of great importance. Gold is obtained from both placer and quartz mines in nearly every county. The first discoveries were made about 1860, and the total output up to 1901 amounted to more than $100,000,000. There has been a decrease in production in late years, owing to the exhaustion of the placer deposits; but with the opening of new fields for quartz mining, such as that at Thunder Mountain, the industry may regain its former prominence. Dredging operations for the recovery of gold from the bed of the Snake River have been carried on successfully for several years. The Cœur d'Alêne lead-silver district in Shoshone County is one of the richest in the United States. The metallic output of Idaho in 1900 was as follows: Gold, $1,727,700; silver, 6,429,100 ounces, valued at $3,986,042; lead, 85,444 short tons; copper, 290,162 pounds.
Forests and Forestry. There are in the State 7,000,000 acres of timber land, the exploitation of which has just begun. Almost the whole of the forest area is in the northern part of the State, where the valleys are covered with an exceedingly dense growth. The larger part (3,456,000 acres) of the Bitter Root Timber Reserve is in Idaho. The higher elevation is known as the alpine fir region, constituting nearly three-fourths of the total reserve, the timber in this part being of little value. In the lower zone the yellow pine occupies the drier regions, and the red fir the more moist regions. The Idaho forests have suffered great losses from forest fires.
Agriculture. A very large part of the State is arid and irreclaimable land. In the north the rainfall is greater, and supplies sufficient moisture for grain crops. Three-fourths of the total area is yet public land. This, however, is being rapidly taken up. The great development of the mining industry has created a home market for farm produce, and justifies incurring the heavy expense of irrigation. The channels of the main streams—the Snake and Clearwater—are generally deep, making irrigation impossible or highly expensive. But numerous smaller streams offer excellent irrigation facilities. This is especially true of the head-water region of the Snake River and of the large district, in the western part of the State, lying north of the Snake River and watered by the Boise River and other streams. The Bear Lake region in the southeast corner is also said to be adaptable to irrigation purposes. In 1900, 602,568 acres, or 42.0 per cent. of the improved land, were irrigated. Five and nine-tenths per cent. of the total area, or 3,204,903 acres, were reported for the same year
