GEOLOGICAL SUEVEY OF THE TEEEITOEIES. 57 



lignite, varying from one to seven feet in thickness, of various degrees 

 of purity. 



In the vicinity of Denver, Colorado Territory, according to Mr. E. L. 

 Berthoud, civil engineer, there are several beds of lignite twelve to 

 eighteen feet in thickness, which must furnish an immense mass of fuel, 

 which will soon become accessible to the people of Nebraska through 

 the Union Pacific Eailroad. 



" Our coal-seams extend, to my knowledge, sixty mile due east from 

 Pike's Peak, in one direction, south to Eaton Mountains and the Eaton 

 Pass, and northward to near Denver, on Cherry Creek, and on the west 

 side of the South Platte as far north as the Cache la Poudre, and to the 

 foot of the main mountain-range. 



" Here, in Golden City, we have a large outcrop of coal, which has 

 been opened successfully, and which inclines toward the town. In one 

 of the newly-opened mines on the same outcrop of the Golden City vein, 

 which lies north on Coal Creek, about nine miles from Golden City, I 

 saw, in 1861, the trunk of a tree taken out of the 11-foot vein then 

 opened and mined, which trunk, though turned into coal of a good 

 quality, exhibited carbonized bark, knots, and woody fiber, with con- 

 centric rings of growth, such as our dicotyledonous trees plainly show ; 

 indeed, one of the miners remarked that, from the bark, and the grain 

 and fiber of the coal, it was very much like bitter cotton-wood, [Populns 

 angulata,) examples of which grow close to the mine. 



" In 1862, while on a scout east of Pike's Peak sixty-five miles, I found 

 a bed of coal almost identical with the Golden City bed, nine feet thick, 

 lying almost horizontal, with bluffs one and a half mile north contain- 

 ing fine specimens of belenmites. 



"Again, in November, 1866, 1 went northeast of Golden City to see 

 the coal-beds on Eock Creek, sixteen to nineteen miles distant. I found 

 beds of coal fourteen to eighteen feet in thickness, almost horizontal, or 

 dipping eastwardly at a small angle 5 above them, ferruginous sand- 

 stone, and vast beds of bog-iron ore and clay iron-stone, in nodules, with 

 numberless fragments of bones. In the sandstone I have obtained fos- 

 sils like Mppurites, but in none of the beds so far have I found a single 

 marine or fresh-water shell, with the exception I have before mentioned. 



" Everything that I have so far seen points out that the coal is either 

 Cretaceous or Tertiary, but I believe it to be Tertiary, or of the same age 

 as the coal near Cologne, on the Ehine; but I am perplexed at the 

 inversion of the dip of the coal, sandstone, and the iron ore, which here 

 incline toward the mountains instead of away from them, and nothing 

 else that I have observed can compare with these tilted- up beds. 



" I have not time now to follow up this subject, nor to give you all 

 the data that I have gathered so far ; I shall report to you in full in 

 regard to the points you mention, but will give you, as soon as time 

 permits, a full report, with elevations, profiles, &c. ; also some speci- 

 mens to prove the relative age of the strata shown in my sketch." 



In the newspapers may be seen advertisements of coal for sale, so 

 much per ton delivered, and so much at the mine. 



This coal, as well as that at Eaton Pass district, is of Tertiary age, 

 and it is questionable whether the true Coal-Measures furnish any coal 

 in any portion of the Eocky Mountain region. 



3d. The Wind Eiver deposits, which occupy an area about one hun- 

 ■ dred miles in length and forty to fifty in breadth. 



These deposits are located between the Wind Eiver and Big Horn 

 Mountains, and are of no economical importance. 



4th. The basin of the Mauvaises Terres, or Bad Lands of White Eiver, 



