848 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



level, forming monument-like points that are visible from a great dis- 

 tance." Slower, probably, in their process of formation, a long time, 

 too, will be required ere these groups yield to final destruction. Massive 

 and solid as the^^ are, they can for ages withstand the attacks of erosive 

 forces. 



STATUESQUE FORMS. 



As such we may designate products of erosion not modelled after one 

 definite type. They are more or less irregular in form, unsymmetrical, 

 and represent not uufrequently figures that a lively imagination can 

 readily compare with well-known subjects of the plastic art, or with 

 animate beings. Popular discrimination has endowed them with names 

 referring to the originals of which they remind the observer. Not only 

 have animate objects and artificial representations thereof been utilized 

 for the comparisons, but even the ruler of the infernal abode has re- 

 ceived tribute in the polite appellations some rocks have received. 

 Were it possible to collect and enumerate all those forms of erosion that 

 within Colorado may lay claim to resemble subjects above named, we 

 should be able to produce a very formidable array. As it is, however, 

 I desire to confine myself to such occurrences which may be regarded 

 as characteristic for the geognostic formations containing them. Defi- 

 nite conditions, both constitutional and active, are requisite for the pro- 

 duction of results referable to this category. Isolated instances are 

 almost innumerable, but cannot enter into consideration here, as their 

 discussion would lead us far beyond our limits. 



WHITE EIVER REGION. 



No locality in Colorado, perhaps, is more favored with exhibitions of 

 statuesque forms than the White Eiver region. West of the one hun- 

 dred and ninth meridian, the light gray and yellow shales of the Tertiary 

 Green Eiver Group are overlaid by massive beds of yellow and brown 

 sandstones. For several reasons, these furnish an almost unequalled 

 material for the production of statuesque forms. While examining 

 that section of country during 1876, every turn led us to new and most 

 grotesque figures. From the river-valley steep walls rise to an elevation 

 of about 1,200 feet. On the summits of the ridges leading down to the 

 stream and on small hills, remaining as evidence of active erosion, we 

 find the groups in question. Appearing at times in the form of walls, 

 simulating ruins of castles of enormous dimensions, the smaller groups 

 may often be compared to statuary or to animate creatures. A certain 

 amount of latitude must necessarily be allowed for the comparison, but 

 not uufrequently the forms are so striking as to suggest, at once, a 

 similarity. Located upon prominent points, such as the summit of a 

 ridge or the top of a small hill, the eroded rocks stand out boldly, 

 changing in outline and relief as the observer changes his position. 

 Thus one rock, about 18 feet high, from a distance appeared as represent- 



