PEALE.] GEOLOGY UNCOMPAHGRE RIVER. 103 



fault at the southern, I am unable to say. The western side of the 

 cafion will have to be studied before the question can be decided. 



Leaving the caiion the Gunnison keeps its westerly course for about 

 six miles, when it makes some southing to the mouth of the Uncom- 

 pahgre, which joins the river eight miles below the foot of the caiion. 



The TJucompahgre is the largest tributary of the Gunnison from the 

 south. It rises in the Uncompahgre Mountains (Sierra de la Plata of 

 Gunnison*), and has a general course a few degrees west of north. The 

 range in which it rises is one of the finest in the Rocky Mountains. 

 The geology will be fully treated of in Dr. Endlich's report, the 

 range being in the southern district. While we were in the valley of 

 the Uncompahgre, we had a magnificent view of its snowy peaks, which 

 stand out prominently against the sky. To the west we had a sight of 

 the Sierra la Sal or Salt Mountains, the peaks being just visible. 



linear the head of the Uncompahgre there seem to be some beautiful 

 open parks. We did not visit them, as our trail led us up Cedar Creek, 

 one of the eastern branches of the river. We were but a few miles 

 above the mouth of Cedar Creek, at the point where the wagon-trail 

 crosses. 



Cedar Creek is probably dry during the greater part of the year. It 

 rises in a plateau-like divide, opposite a small branch of Cebolla Creek, 

 a few miles west of the mouth of the main stream. Its general course is 

 about northwest. The upper portion of the valley is narrow and ravine- 

 like, the slopes of the hills being covered with scrub-oak. sage, and 

 cactus, with here and there patches of grass. This valley continues for 

 about ten miles, when the creek comes out into the broad valley of the 

 UncompahgTe, which at this point has lines of buttes of light-colored 

 clayey-beds, the debris of which forms a soft soil, in which the mules sink 

 to their fetlocks at every step. All the small creeks, dry for the greater 

 part of the year, cut deep gullies in this soft soil, which is almost desti- 

 tute of vegetation. In places there is considerable efQoresence of alkali, 

 and gypsum is found abundantly throughout the valley. The buttes 

 are found on the eastern side of the valley. They are from two hundred 

 to four hundred feet high, and form two lines, those nearest the canon 

 of the Gunnison being the highest. The buttes are not so numerous 

 in the lower jjart of the valley, where the genej:'al level is bat a few feet 

 above the river-bed. It is more plain-like, without grass, having only a 

 sparse growth of lov/ sage, interspersed with spots of alkali, giving 

 the country a most desolate aspect. Along the river is an alluvial 

 bottom, with good grass, the river being bordered with cotton woods, 

 willows, and low bushes of various kinds. This bottom becomes mach 

 wider as we descend, and is a favorite wintering place for the Ute In- 

 dians, We found traces of their camps, while their trails run in every 

 direction. In one place we found a field where corn had been raised, the 

 stalks of which weie still standing. 



On the opposite side of the Uncompahgre the country preserves a 

 very uniform level for ten or fifteen miles to the west and southwest, 

 where it seems to rise in a plateau. This level country is terraced, cut 

 by the branches of the Gunnison and Uncompahgre, which contain 

 water only in the .s^jring. The terraces are for the greater part desti- 

 tute of vegetation, being coverd with pebbles, among which are scattered 

 fragments of chalcedony and agate. They are underlaid with Creta- 

 ceous strata, shales in the eastern part, and the sandstones of the Da- 

 kota group toward the west, as the country rises into the plateau. The 



* Pacific Railroad Report, vol, ii, page 55. 



