352 Expedition to tht 



swells of greater or less extent, which contribute to give a 

 pleasing variety to the prospect. The country is also divided 

 into extensive parterres by the vallies of rivers and creeks, 

 which are usually sunk one hundred and fifty or two hundred 

 feet below the common level, and bounded in some places by 

 perpendicular precipices, and in others by bluffs or banks of 

 gentle slopes. 



Immediately at the base of the mountains, and also at 

 those of some of the insular table-lands, are situated many 

 remarkable ridges, rising in the form of parapets, to the 

 height of between fifty and one hundred and fifty feet. 

 These appear to have been attached to the neighbouring 

 heights, of which they once constituted a part, but have at 

 some remote period, been cleft asunder from them, by some 

 extraordinary convulsion of nature, which has prostrated 

 them in their present condition. The rocky stratifications, 

 of which these ridges are principally composed, and which 

 are exactly similar to those of the insulated table-lands, are 

 distinctly marked, and have various dips, or inclinations, from 

 forty-five to eighty degrees. 



Throughout this section of country the surface is occasion- 

 ally characterized by water-worn pebbles, and gravel of gra- 

 nite, gneiss, and quartz, but the predominant characteristic is 

 sand, which in many instances, prevails almost to the entire 

 exclusion of vegetable mould. Large tracts are often to be 

 met with, exhibiting scarcely a trace of vegetation. The 

 whole region, as before hinted, is almost entirely destitute 

 of a timber growth of any description. In some few instances, 

 however, sandy knobs, and ridges make their appearance, 

 thickly covered with red cedars of a dwarfish growth. There 

 are also some few tracts, clad in a growth of pitch pine, and 

 scrubby oaks; but in general, nothing of vegetation appears 

 upon the uplands, but withered grass of a stinted grov/th, no 

 more than two or three inches high, prickly-pears profusely 

 covering extensive tracts, and weeds of a few varieties, which, 

 like the prickly-pears, seem to thrive best, in the most arid 

 and sterile soils. 



In the vicinity of the Rocky Mountains, southwardly of the 

 Arkansa river, the surface of the country, in many places, 

 is profusely covered with loose fragments of volcanic rocks. 

 On some occasions, stones of this description are so numer- 

 ous, as almost to exclude vegetation. A multiplicity of ridges 

 and knobs of various sizes, containing rocks of this character, 

 also make their appearance. All these formations seem to be 



