134 TEN DAYS IN MONTANA. 



them is one of the impossibilities of the English language. 

 Geologists who have examined them have various theories as 

 ta their origin ; but the most common one, and that which 

 appears to me most tangible, is, that at some remote period 

 there were great internal convulsions of the earth, something 

 of the nature of earthquake, that, owing to the- existence o 

 extensive subterranean caverns, at no great distance below, the 

 crust or surface gave way and dropped, to distances varying 

 in different localities, from two hundred to five hundred feet. 

 The bases or floors of these caverns must have been very un- 

 even. Apparently there were, in places, great ledges or pillars 

 of granite or other solid formation, towering to great heights 

 from these floors. On these projections this falling mass must 

 have struck, and portions of it were held in suspense, while 

 the remainder passed on down to the general level base of 

 the caverns. The general surface passing down left these por- 

 tions of it which first met with resistance protruding through, 

 and thus were formed great buttes, peaks, mounds and 

 pryamids, of all sizes, heights, shapes and colors that the 

 most speculative mind could possibly imagine. 



Then, either before or after these great convulsions, inter- 

 nal fires have raged, perhaps for ages. Rich deposits of coal 

 or lignite have in some manner become ignited and burned 

 away, leaving other cavities -which have in turn been filled up 

 by the sinking crust. There are many-distinct and well de- . 

 fined craters, long since extinct, around which lie masses of 

 lava, scoria, lime and baked clay. Some of the buttes where 

 these extinct craters are found are covered all over with red 

 clay, baked to the consistency of brick or pottery, and broken 

 into small pieces, looking as if thousands of crates of pottery 

 might have been broken up and piled there by the hand of 

 man. Then, since these scenes were enacted, another de- 

 stroying element, water, has wrought its ravages, uninter- 



