ISO!).] -^ [Hayden. 



lar layers of sandstones ; at other times inclosing concretions, with con- 

 centric layers or composed of thin laminas and readily cleaving in pieces 

 on exposure to the atmosphere. Immediately underneath the coal lies a 

 bed of drab clay varying in thickness from three to five feet. The first 

 locality where the coal is exposed by the uplifting of the beds is near a 

 small lake. The dip is about 10^* towards the north-east and from the 

 mountains. There is about six to eight feet of pure and impure coal 

 together. Above, is a bed of drab clay ; and over this again a layer of 

 fine grit, capped with hard sandstone. The clay over the coal is full of 

 small rounded nodules of iron and yellow sandy concretions. 



About a mile west from this locality is another outcropping of coal. 

 The bed is here separated by about 2} feet of drab arenaceous clay, with 

 five -feet of excellent coal above and six to eight feet below, making in 

 all from ten to twelve feet of solid coal. Some of it has a dull bitumi- 

 nous look, other portions are as glistening and black as anthracite. 

 Above the coal is the usual clay bed, many layers in which are largely 

 comi)osed of the stems and leaves of plants. Above this there are beds 

 of loose rusty brown sand and sandstone with some ferruginous concre- 

 tions ; and a layer of light brown very compact silicious rock caps the 

 hill. The dip of the beds is not more than 3^ to 5^. At tke immediate 

 entrance to the mine the^ inclination is about 5^. The coal can be easily 

 wrought and the mine well drained, in spite of its clay roof. The coal 

 is of excellent quality, but like most of the broAvn coals of the west, 

 crumbles on exposure to the atmosphere, as appears from the condition 

 already of the large coal heaps in front of the mine. 



So far as I have been able to ascertain, I am incliiied to believe that 

 the coal bed already alluded to is the lowest in the region and identical 

 with the one so successfully worked at Carbon Station on the line of the 

 Union Pacific Eailroad ; but I do not think that it is the oldest coal bed 

 in the tertiary series of the West. 



The valley of Rock creek is from three to five miles in width and evi- 

 dently a valley of erosion. On the west side of it there is a ridge at 

 least 500 feet high, composed of tertiary beds, which in some places 

 incline 10° to 15°, but the general dip is not more than 5°. 



On both sides of the stage road for ten miles west of Bock creek there 

 is a large area covered with huge piles of rusty brown sandstone, mostly 

 concretionary. In some localities a great many impressions of deciduous 

 leaves were found. The tertiary beds extend to the mountains and form 

 a large part of the foot hills. Here lofty wall-like exposures of sand- 

 stone make their appearance, giving a very rugged appearance to the 

 country. As far as the eye could reach we saw peculiar looking pyramidal, 

 conical and dome-shaped hills, from 300 to 500 feet high, composed of 

 alternate layers of rusty yellow sandstone and greenish gray indurated 

 sands, which are sometimes in the valleys of streams exposed for a thick- 

 ness of 1000 or 1500 feet. These beds incline gently from the mountains, 

 about north-east. 



Since crossing the Big Laramie river exposures of the red beds have not 



