COAL. 371 



other openings. — Other openings in this held, from which coal is said to 

 have been shipped for local trade, are now abandoned. Of these, four are 

 near the Baker mine, and two, the Eulner and Chessey, 2 or 3 miles n< irtheast. 



There are doubtless localities in this great area east of Coal Creek 

 which carry in depth, workable beds of coal, but they will remain unknown 

 till the coal trade is far greater than at present and the more accessible 

 areas already opened are well on toward exhaustion. 



WHITE ROCK AREA. 



The White Rock coal area lies just beyond the northern edge of the 

 Denver held, on the northern side of Boulder Creek, about 6 miles west of 

 Erie. At this point a prominent hill rises some 350 feet above the creek 

 level, its southern and western slopes the steeper, its northern and eastern 

 very gentle. The hill is composed almost entirely of the basal sandstones 

 and coal measures of the Laramie, only the lowest beds of the tipper 

 Laramie underlying the heavy cap of Quaternary. Along the southern 

 base of the hill the sandstones of the Fox Hills occur in local outcrops. 

 The basal sandstones of the Laramie complete the bluffs, carrying the No. 

 1 seam, which is here but a succession of thin layers of coal, sand, and 

 slate, in all 2 to 3 feet. 



Above sandstones A and B are the coal measures, but they appear only 

 in occasional outcrops. The coal occurs in a shaft (now long abandoned) 

 near the summit of the hill; it is said to lie about 40 feet over sandstone B, 

 and is therefore one of the higher seams of the series. It was regarded 

 as of little value. 



The strata of the area have a general N. to N. 20° E. strike, with an 

 easterly or east-southeasterly dip of 5° to 10° over the more regular 

 portions. The northern slope of the hill lies beyond the limits of the map 

 and the details of its structure were not attempted. 



OTHER MINE LOCALITIES OF THE LOWER LARAMIE COAL MEASURES IN THE 

 VICINITY OF THE DENVER BASIN. 



Several mines in the lower Laramie coal measures lying wholly north 

 of the area defined for exploration have been periodically worked in the 



