272 • Description of pari of Wyoming Territory. 



\vhen the country teemed withlife, I truly felt that I was standing on 

 the wreck of a former world. 



The buttes are often especially designated from some supposed re- 

 semblance, or other character, as Church Butte, Pilot Butte, Grizzly 

 Butte, etc. 



As before intimated, the more superficial table-lands of the Bridger 

 basin, as they appear m the vicinity of Fort Bridger, are composed of 

 nearly horizontal strata of various colored, indurated clays and sand- 

 stones. In most localities visited by the writer the clays predominate, 

 and are usually greenish, gi-ayish, ash-colored, and brownish. When 

 unexposed they are compact, homogeneous, and of stony hardness. 

 In composition they vary from nearly pure clay to such as are highly 

 arenceceous, and gradate into those in which sand largely predominates, 

 and they usually contain few or no pebbles. They appear to be more 

 or less fissured, and break with an irregular and somewhat couchoidal 

 fracture. Exposed to atmospheric agencies, moisture and frosts, they 

 readily disintegrate, and the declivities of the buttes, generally en- 

 tirely destitute of vegetation, are usually invested with crumbling 

 material from a few inches to a foot or more in depth. Yv'hen this 

 loose material is wet it forms a tenacious mud, and along the course of 

 stireams in the ravines, the deepest and most treacherous mire. Baked 

 by the sun upon the plains, it fixes the drift pebbles and other stones 

 as firmly almost as if imbedded in mortar. 



In some localities the clays of the buttes abound in freshwater 

 shells, as Unio, Melania, Plauorbis, etc. Less frequently in other 

 places they contain land-shells, as Helix, etc. 



The sandstones are more frequently of various shades of green, but 

 are also yellowish, and pass into shades of brown. They are compact 

 and hard when unexposed to the weather, and are usually fine-grained, 

 but also occur of a gravelly constitution. They are fissured in com- 

 paratively large masses, wdiich assume a rounded form as they are worn 

 away, so that a ledge of sandstone projecting from the declivity of a 

 butte will appear like a row of cotton bales. As they disintegrate less 

 rapidly than the contiguous clays, masses are often o])served resting 

 upon cones and columns of the latter. contri])uting greatly to the 

 picturesque and sometimes fantastic appearance of the buttes. 



Many of the table-lands and lesser buttes in the vicinity of the 

 Uintah Mountains are thickly covered with drift from the latter, con- 

 sisting of gravel and bowlders, of red and gray, compact sandstones, 

 or quartzites. The drift material is usually firmly embedded in the 

 surface of the plains, so as to appear like a pavement. The bowlders 

 are generally small, but assume larger proportions, approaching the 



