GEOLOGICAL SURVEY OF THE TERRITORIES. 79 



of influence over the progress of the great West that those of Pennsyl- 

 vania do over the contiguous States. " When we reflect that we have 

 from 10,000 to 20,000 square miles of mineral fuel in the center of a 

 region where, for a radius of COO to 1,000 miles in every direction, there 

 is little or no fuel either on or beneath the surface, the future value of 

 these deposits cannot be overestimated." 



At the source of the Chugwater, about 30 miles north of Cheyenne 

 City, there is a vast deposit of magnetic-iron ore of the best quality. 

 Through the kindness of my friends Dr. Latham and Mr. Whitehead, 

 citizens of Cheyenne City, I had an opportunity to visit these iron-mines, 

 and 1 found them much richer and more extensive than I had previously 

 imagined. Iron bowlders of this ore have been found in the valley of 

 the Chugwater for many years. In the report of Captain Stansbury the 

 following paragraph is found : 



In the bed of the Chugwater and on the sides of the adjacent hills were fonud im- 

 mense numbers of rounded black nodules of maguetic-iron ore, which seemed of unusual 

 richness. 



In the winter of 1859, I gathered a large number of specimens of this 

 erratic ore, which seems to be scattered in the greatest quantity through- 

 out the valley of the Chugwater ; the snow was so deep that I could not 

 trace these masses to their source. This season I followed these erratic 

 masses up the valley of the Chugwater, and in the mountains, inter- 

 stratified with the metamorphic rocks, probably of Laurentian age, were 

 literally mountains of this magnetic ore. Mr. Whitehead traced one of 

 the beds a distance of 1^ miles. It occurs in mountain-like masses similar ' 

 to the ore-beds on Lake Superior. 



Mr. J. A. Evans, engineer of construction, who made a careful explora- 

 tion of these ore-beds, thinks that the ore can be transported from the 

 Black Hills to the Laramie Plains, and then smelted with the coal which 

 is found in the greatest abundance along the line of the railroad. Pro- 

 fessor Silliman is of the opinion that the two ores, the magnetic ore of 

 the Laurentian epoch and the brown hematites of the Tertiary beds, can 

 be more easily reduced by mixing them together. In that case, Chey- 

 enne City would be the most desirable point for the erection of a rolling- 

 mill orfurnace. The Union Pacific Railroad contemplates erecting several 

 rolling-mills along the line of the road, and when this is done these ores 

 will come into demand. 



In regard to the coal of this country, the evidence seems to be clear 

 that it is probably all of the Tertiary age. I have traced it over a vast 

 area on the Upper Missouri Eiver, and it seems probable that it extends 

 far northward toward the Arctic Sea. I have also traced the Lignite 

 coal-beds from the Yellowstone Valley, by way of the Big Horn Mount- 

 ains, to the North Platte, until they pass beneath the White Eiver Ter- 

 tiary beds, about 80 miles north of Fort Laramie. These beds re-appear 

 again about 10 miles south of Cheyenne City, and continue uninterrupt- 

 edly to the Arkansas. On the west side of the Laramie range these 

 beds appear again a few miles east of Bock Creek, and from there con- 

 tinue westward to Salt Lake and perhaps farther. 



In Colorado these coal-beds have been wrought to considerable ex- 

 tent. At South Bowlder Creek there are 11 beds of coal varying in thick- 

 ness from 5 to 13 feet. The lowest bed is 13 feet in thickness, and is of 

 excellent quality, very much resembling anthracite in appearance, 

 though much lighter. An analysis of this coal by Dr. Torrey, of New 

 York, shows it to contain 59.20 per cent, of carbon ; water in a state of 

 combination or its elements, 12.00 ; volatile matter, expelled at a red 

 heat, forming inflammable gases and vapors, 26.00; ash of a reddish. 



