J8i;.-'.] ^Q^ [llay.UMi. 



I would here cull attention especia,ll\^ to some beds of fine 

 "rained conii)act sienite along the line of the Union Pacific Rail 

 Road, near the summit of the first range, which nearl}- equals 

 the best Scotch sienite, and resembles it very closely. The 

 Union Pacific Rail Road contemplate transporting this beautiful 

 rock to Omaha, to construct with it the piers of the bridge 

 across tlie Missouri River. I regard this sienite to be as dur- 

 able, and more elegant for building purposes than Quincy granite. 

 One of the most important problems for solution afi'ecting the 

 prosperity of this portion of the West, is the possibility of util- 

 izing the vast quantities of coal and iron with which this country 

 abounds. All the coals of Wyoming and Colorado appear to be 

 of Tertiary age ; and so extensive are they in the West, that it 

 becomes a question Avhether the Tertiary' might not with more 

 propriety be called the Carboniferous or coal bearing period. I 

 have estimated the coal area north of the Arkansas, south of 

 Lodge Pale Creek, and east of the mountains, at five thousand 

 square miles. It is quite possible that a more careful examina- 

 tion will show that it covers a still larger area. 



In connection with this coal are large deposits of brown iron 

 ore or limonite. Vide LeConte's Report, p. GO. There is no evi- 

 dence as yet that the heat-producing power of these coals is suf- 

 ficient to reduce iron. This iron ore occurs in the form of nod- 

 ules or concretions, var^dng in size from an ounce to several 

 hundred pounds in weight. It resembles ver^^ closely the iron 

 ore of Maryland and Pennsylvania. It seems to be coextensive 

 with the coal beds, though occurring more abundantly at some 

 localities than at others. About twelve miles south of Cheyenne 

 City there are large quantities, and within a few miles, beds of 

 coal five to six feet in thickness are now worked. At South 

 Boulder Creek it occurs again in great quantities, scattered 

 through twelve to fifteen hundred feet of sands and clays con- 

 nected with the coal. It will doubtless be found in the form of 

 carbonate of iron beyond the reach of atmospheric influences. 



The first smelting furnace erected in Colorado was established 

 Ijy Mr. Josei)h Marshall, and he informed me that it required 

 about three tons of ore to make one ton of pig iron. Over five 

 hundred tons of this ore have been taken from this localitj^, and 

 the area occupied by it is over fifty square miles. 



There are many other localities on both sides of the moun- 

 tains where this form of iron ore abounds. 



At the sources of the CherrjMvater, about thirt}' miles north 

 VOL. X. — 3l 



