50 GRAND CANON DISTRICT 



For convenience of geological discussion Professor Powell has divided 

 that belt of country which lies between the meridian of Denver, Colo., 

 and the Pacific and between the 34th and 43d parallels into provinces. 

 each of which possesses topographical features which distinguish it from 

 the others. The easternmost he has named (he Park Province. It is 

 situated in the central and western parts of Colorado and extends north 

 of that state into Wyoming and south of it into New Mexico. It is pre- 

 eminently a mountain region, having several long ranges of the second 

 order of magnitude. The structure and forms of these mountains are 

 not exactly similar to those of any other region now well known, but 

 possess some resemblance to the Alps, though not a very close one. 



As we pass westward of these ranges in Colorado we enter, near 

 the western boundary of that state, a region having a very different to 

 pography. The mountains disappear almost wholly, and in their stead 

 we find platforms and terraces nearly or quite horizontal on their .sum 

 mita or floors and abruptly terminated by long lines of cliffs. They be 

 at greatly varying altitudes, some as high as 11,000 feet above the sea, 

 others no higher than 5,000, and with still others occupying intermediate 

 levels. Seldom does the surface of the land rise into conical peaks or 

 into long narrow crested ridges; but the profiles are long, horizontal lines 

 suddenly dropping down many hundreds or even two thousand feet 

 upon another Hat plain below. This region has been very appropriately 

 named, by Powell, the Plateau Province. It occupies a narrow strip in 

 the extreme western part of Colorado, a similar strip of western New 

 Mexico, a large part of southern Wyoming, and rather more than half 

 of Utah and Arizona. 



West of the Plateau Province is the Great Basin, so named by Pre. 

 mont because it has no drainage to the ocean. Its topography is wholly 

 peculiar and bears no resemblance to either of the two jnsl alluded to 

 It contains a large number of ranges, all of which are verv narrow and' 

 short, and separated from each other by wide intervals of' smooth bar 

 ren plains. The mountains are of a low order of magnitude for the 

 most part, though some of the ranges and peaks attain considerable 

 dimensions. Their appearance is strikingly different from the noble 

 and picturesque outlines displayed in Colorado. They are jagged wild 

 and ungraceful in their aspect, and, whether viewed from faTor'ne ,/ 

 repel rather than invite the imagination. 



The Wasatch, however, is an exception. This noble range is properly 

 a part of the Basin Province, and is one of the finest and mos pi n 

 esqueof the West, but so completely does it contrast with the • 



Basin ranges that it may be regarded as an anomaly among then, The 

 topographical features of this region are also found outside of t ho I 

 tewhmh Fremont assigned to the Great Basin, and reach sout w l 

 into Arizona and northward into Idaho and Oregon Tbp b, ™ , , 

 covers the western part of Utah, nearly the whl o^^Zl 

 small portion of southern Oregon and Idaho Tt« » V 7^, 

 the base of the Sierra Nevada? * "****** ^^^ te 



