ROCK RIVER 



ROCKY MOUNTAINS 



757 



with flowers in imitation of the natural conditions 

 in which the Alpine flora appears in Alpine regions 

 and in high latitudes. 



Rock River rises in the south-eastern portion 

 of Wisconsin, and flows south into Illinois, thence 

 south-west, and empties itself into the Mississippi 

 3 miles below Rock Island. Its course of 375 miles, 

 much broken by falls, is through a region noted for 

 its beauty and fertility. 



Rock-rose. See CISTUS. 



Rock-salt. See SALT. 



Rock-soap, a mineral consisting of silica, 

 alumina, peroxide of iron, and water, the silica 

 nearly one-half, the alumina and the water some- 

 times nearly each one-fourth of the whole. It is 

 earthy, easily broken, black or nearly so, very soft, 

 and easily cut with a knife, is greasy to the touch, 

 and adheres strongly to the tongue. It is valued 

 by painters for crayons. It is found in Poland, 

 Tnuringia, and Bohemia, and occurs in basaltic- 

 rocks in the Isle of Skye and Antrim, in the form 

 of nodules of a greenish-gray or brown colour. It 

 is only found massive. 



Rock-temples. In many parts of Western 

 India, as at Ellora, Elephanta, Karli, and Salsette 

 Island, natural rocks have been cut into temples ; 

 as also into caves and forts ( see the articles men- 

 tioned ). Out of India well-known instances of the 

 same kind occur at Petra (q. v. Jin the Arabian 

 Desert, at Abu-Simbel (q.v.) in Egypt, and in 

 China and Siam. There are remarkable cave- 

 temples in the United States, one in Missouri, 

 between the Salt River and Otter Creek, and 

 another near Manchester in Ohio. The rock-dwell- 

 ings of Colorado, &c. , are described at CAVE. See 

 James Fergusson, Rock-cut Temples of India ( 1864), 

 with seventy-four photographs by Major Gill. 



Rocky Mountain Goat (Aplocerus), a 

 beautiful animal of the antelope family, which 

 inhabits the heights of the Rocky Mountains be- 

 tween the forests and the snow-line, from the 44th 

 to the 65th degree of latitude. It is about the size 

 of a goat, but is handsomer and more thickset, and 

 has stronger legs. It is completely covered with 

 long, thick, white hair, which forms an erect mane 

 along the middle of the back from between the 

 horns to the root of the tail. Though it is hunted 

 by the trappers, its flesh is not valued as food. 

 The above species and the Prong-horned antelope 

 (Antilocapra) are the only antelopes which occur 

 in the New World. For the Rocky Mountain 

 Sheep, see AROALI, SHEEP. 



Rocky Mountains, formerly a name some- 

 what loosely applied to ail the mountains of North 

 America between the Great 

 Plains ami the Pacific Ocean, but 

 now a term used todesignateonly 

 the eastern ranges of the great Cordilleran system. 

 This vast mountain-system acquires its greatest 

 breadth within the limits of the United States, 

 where between the parallels 38 and 42 N. lat. ib 

 attains a width of more than 1000 miles. Toward 

 the north and the south the plateaus of this high- 

 land gradually diminish in breadth, but they are 

 enclosed on the east and on the west by high moun- 

 tain-chains. Those forming the western boundary 

 are the Sierra Nevada and the Cascade Ranges 

 (q.v. ), and the eastern chains stretching with unin- 

 terrupted continuity from the southern borders of 

 tli>' I nited States through the Dominion of Canada 

 to the Arctic Ocean constitute the Rocky Moun- 

 tains. Between these eastern and western bound- 

 aries the plateau region is greatly diversified by 

 chains which, as a rule, trend in the same general 

 direction as the border ranges. 



The name ' Rocky Mountains ' is peculiarly 



Copyright 1891. 1897, and 

 1900 In the U. S. by J. B. 

 LIpplDcolt CompaDj. 



appropriate, as there probably exists nowhere else 

 such an extensive region of naked rock almost 

 entirely devoid of vegetation. The geological 

 structure is complex, but the greater part of the 

 rocks exposed are Mesozoic intermingled with 

 Tertiary and Quaternary deposits. As this system 

 is consequently of mucn more recent origin than 

 the Appalachians, it is naturally higher, and it 

 presents also a sharper and more rugged outline. 

 Its remarkably barren aspect is due also to other 

 geological peculiarities and to climatic causes. In 

 comparatively recent ages this whole region has 

 been the scene of vast volcanic eruptions, and the 

 lava overflows which have- covered the stratified 

 rocks in many places to a depth of thousands of 

 feet have augmented the expanse of sterile surface. 

 By resisting the erosion of the streams and of the 

 atmosphere, these lava beds have also greatly 

 aided in producing the precipitous and deeply 

 furrowed watercourses by which this wonderful 

 plateau region is traversed. The high mountain 

 barrier at the western boundary of the highland 

 robs the winds which sweep across the Pacific of 

 much of their moisture, and the great aridity of 

 this region thus prevents the growth of vegetation. 

 The surface is consequently exposed to continued 

 erosive action, which is specially rapid at such great 

 elevations. The denudation is the more complete 

 as the sand and smaller disintegrated fragments 

 are swept away by the winds, and no opportunity 

 is afforded for the accumulation of a soil. On 

 account of these various causes the erosion of the 

 surface is uneven, and the region displays a 

 labyrinth of naked crags and peaks arising from 

 plateaus crossed by towering cliffs or deep canons, 

 with here and there an isolated butte. The scenery 

 of the wonderful mesa or plateau region which lies 

 between the eastern and western ranges of the 

 Rocky Mountains, and extends from southern 

 Wyoming through western Colorado, eastern 

 Utah, and south into New Mexico and Arizona, 

 is unequalled by that of any other portion of the 

 globe. The country is divided by faults, flexures, 

 and deep canons into numerous blocks or separate 

 plateaus, and the wonderful carving of the rocks 

 and the brilliant colouring of the exposed strata 

 almost surpass belief. 



A high plateau region in Wyoming, over which 

 passes the Union Pacific Railroad, marks a separa- 

 tion of the Rocky Mountains into a northern and 

 a southern group, each of which has its characteristic 

 features. The continental divide which extends 

 north and south with the ranges of the Rocky 

 Mountains culminates in this plateau, where are 

 found the extreme head-waters of the three great 

 river-systems of the United States the Mississippi, 

 the Columbia, and the Colorado. The ranges of 

 the southern group have a general north and south 

 trend, and are higher than those of the northern 

 group. As there are several elevated valleys known 

 as 'Parks' enclosed between the parallel ranges, 

 this group is sometimes known as the Park System. 

 It extends southward from the Laramie Plains 

 across central Colorado into New Mexico. Its 

 greatest development is in Colorado, where there 

 are nearly forty peaks each over 14,000 feet in 

 height. The Medicine Bow Range and the Colorado 

 or Front Range form the eastern edge of the Rocky 

 Mountain System, and rise abruptly from the 

 gentler slope of the Plains. In this range are the 

 well-known landmarks, Long's Peak (14,271 feet) 

 and Pike's Peak (14,134 feet), as well as Gray's 

 Peak (14,341 feet), its highest point, which is too 

 far west to be visible from the Plains. This range 

 forms the eastern wall of North, Middle, and 

 South Parks, and the Park Range constitutes their 

 western boundary. To the west of the southern 

 end of the Park Range lies the Sawatch Range, 



