49 



Hayden.] ^ ■^ [February 19, 



not be identical, and in some cases not even very similar. The more 

 recent the age of formations the less persistent seem to be their litholo- 

 gical characters over extended ai'eas. 



Although the coal beds seem to be abundant everywhere along the line 

 of the road in the lower tertiary deposits, they have been wrovight as yet 

 in few localities. Near Point of Eocks Station, about 45 miles east of 

 Green river, one of the best coal mines I have yet seen in the West has 

 been opened, and Mr. W. Snyder, the able Superintendent of the Union 

 Pacific Railroad, has ordered a side track to be laid to it about a quarter 

 of a mile long. Five coal beds have been opened in a vertical height of 

 80 feet. The lowest is about 100 feet above the bed of the creek. They 

 are respectively 5, 1, 4, 3 and 6} feet thick. The five foot bed is the 

 most valuable, and as the strata are nearly horizontal it can be worked 

 with ease and free of water. The hard, compact coal is pitched down 

 the sides of the hill more than a hundred feet without being broken by 

 the fall. It is 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. Several other beds are in these hills which have not 

 yet been examined. Near the summit of the hills, above the coal beds, 

 there is a seam six inches thick composed entirely of oyster shells, about 

 the size of the common edible oyster, but of a distinct and probably nn- 

 described species. 



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

 of Rocks, at Rock Spring. It is about 4 feet thick, with a bed of sand- 

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

 advantage. 



Scattered all through the coal-bearing strata are seams and concretions 

 of brown iron ore in abundance, sometimes persistent over extensive? 

 areas, and varying from 4 to 12 inches in thickness. The ore occurs 

 mostly however in a nodulai* form, and much of it can be made of 

 economical value when there is a demand for it. There are also numer- 

 ous Chalybeate and Sulphur springs with excellent medicinal proi^erties. 



Near Rock Springs fresh water beds again incline nearly west 6^ to 10°, 

 but apparently diff'erent from those between Creston and Bitter creek. 



The beds exposed at this point are made up of drab clays, sometimes 

 a little sandy, with heavy beds of gray and rusty yellow easily disinte- 

 grating sandstones. There are also in the clay beds quite thick beds of 

 coal which have ignited spontaneously and baked the superincumbent 

 layers, in many cases melting the rock. There is very little vegetation 

 on these hills, only now and then a dwarf cedar. 



Near the summit of the hills there is a thin layer of limestone com- 

 posed of an aggregate of small melanias. 



From Rock Spring to Bryan the rocks present a peculiar appearance, 

 occurring mostly in thin laminae or layers like slate. There are 300 to 

 500 feet of these drab gray laminated shales, and above them, capping 

 the hills about Green river, are from 300 to 500 feet of rusty yellow 

 shales, which are weathered into castellated forms. 



