spruce forest near which the fire started but 

 which it did not reach for a week. These men 

 said that, an hour or so after a thunder-shower 

 of a few days before, one of the brown beetle- 

 killed pines had sent up a smoke-column. Ap- 

 parently lightning had struck this tree. The 

 following day a small fire was burning near it. 

 This expanded into the forest fire. Commonly 

 it is a standing dead tree that is set on fire by 

 the lightning, but the bolt sometimes fires ac- 

 cumulated trash around the roots where it 

 enters the earth. 



Within this extensive burn the trees had 

 stood from thirty to one hundred and forty feet 

 high and from two hundred to three thousand 

 to the acre, and they were from thirty to four 

 hundred and fifty years old. A majority were 

 about two centuries old. The predominating 

 kinds were yellow pine, Douglas spruce, Engel- 

 mann spruce, and aspen. Different altitudes, 

 forest fires, and a variety of slope-exposures, 

 along with the peculiar characteristics of each 

 species, had distributed these in almost pure 

 stands, an area of each kind to itself. There was 



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