100 GEOLOGICAL SUEVEY OF THE TERRITORIES. 



W. Snyder, the able superinteudent of the Union Pacific Eailroad, has 

 ordered a side-track to be laid to it, about a quarter of a milie distant. 



Within a vertical height of 80 feet five coal-beds have been opened. 

 The lowest is about 100 feet above the bed of the creek. They are re- 

 spectively five, one, four, three, and six and one-half feet in thickness. 

 The five-foot bed is most valuable, and as the strata are nearly hori- 

 zontal, it can be worked with great ease and freedom from water. The 

 coal is brought from the mine and thrown down the sides of the hill a 

 hundred feet fall or more, and yet so hard and compact is the coal that 

 it is not broken by the fall. It is also purer and heavier than any coal 

 I have yet seen west of the Laramie Mountains. The other beds already 

 opened will yield moderately good coal. There are several other beds 

 ia these hills which have not yet been examined by the miner. 



Near the summit of the hills, above the coal-beds, there is a seam 

 composed entirely of oyster-shells six inches thick. It is about the size 

 of the common edible oyster, but an extinct and probably undescribed 

 species. 



Another bed of coal has been opened about 28 miles west of Point of 

 Eiocks, at Eock Spring. It is about four feet thick, with a bed of sand- 

 stone at the bottom, and a slaty-clay roof. It cannot be worked to ad- 

 vantage. Scattered all through the coal-bearing strata are seams and 

 concretions of brown iron ore in great abundance. Sometimes these 

 seams are quite persistent over extended areas, and vary from four to 

 twelve inches in thickness. It occurs mostlj^, however, in a nodular 

 form, and assumes a great variety of characters. There is much of it 

 tliat can be made of economical value where there is a demand for it. 

 There are also numerous chalybeate or sulphur springs in that region, 

 which possess excellent medicinal properties. 



In this brief account of the country lying west of the Laramie Mount- 

 ains and east of Green Eiver we have shown that vast quantities of coal 

 exist, of the best quality, and that in intimate connection with it are 

 valuable deposits of iron-ore. We also believe that within a few years 

 these deposits of iron and coal will be found to be of infinite value to the 

 Union Pacific Eailroad, and that the future success and value of the 

 stock of this road is dependent on these minerals, especially the coal. 

 Mr. Van Lennep, connected with the Union Pacific Eailroad as geolo- 

 gist, described more than fifty localities where the coal crops out to the 

 surface not far distant from the line of the road. A more careful exami- 

 nation for practical purposes I am convinced would reveal the existence 

 of coal and iron in hundreds of localities from Eock Creek to the neigh- 

 borhood of Salt Lake, and there are indications that thej?^ exist even be- 

 yond this point in different directions. 



We have taken the position, also, that the coal-bearing beds of the 

 Laramie Plains are of Tertiary age, although some marine fossils are 

 found in strata connected with the coal. There may possibly be some 

 thin seams of impure coal in the Upper Cretaceous beds, as if the great 

 period of vegetation and the storing np of coal in the West was fore- 

 shadowed in the Cretaceous. At any rate, the Upper Cretaceous beds 

 contain a great amount of vegetable matter, but mostly too obscure for 

 determination. 



So far as I can determine, the growth of the continent forward in 

 time from the Cretaceous period seems to have been constant. I can find 

 no break in time ; no want of conformity between the Tertiary and Cre- 

 taceous beds; and, indeed, so gradually and imperceptibly do the Cre- 

 taceous beds pass up into those of the Tertiary, that I have not been able 

 to determine the line of separation. 



