AREAL DISTRIBUTION OF THE LIGNITIC FORMATIONS. 5 



or six hundred and twenty miles from Mandan Village. Even above this 

 point, washed coal continually appeared on the shores of the river, and at 

 Elk Rapids, eight hundred miles from Fort Mandan, the high bordering 

 bluffs were still composed of horizontal beds of clay, brown and white sand, 

 soft, yellowish-white sandstone, hard, dark-brown freestone, and large, round, 

 or kidney-shaped nodules of clay iron ore. Coal, or carbonated wood, similar 

 to that previously observed, was also seen, and was accompanied with burnt 

 earth, probably the result of the spontaneous combustion of the coal, as was 

 noticed for hundreds of miles below. After reaching the Grand Fork of the 

 Missouri, and ascending two or three days' journey up Maria's River north- 

 ward, it was remarked that precisely the same geological character and coal 

 strata prevailed for more than sixty miles. So far, therefore, the exploring 

 party had been traveling through or over a ligneous deposit of singularly 

 uniform character for no less than nine hundred and eighty miles, following 

 the windings of the river. Pursuing the South Fork toward the Great Falls 

 of the Missouri, coal was still observed in bluffs of dark and yellow clay at a 

 distance of two thousand four hundred and fifty-four miles up that mighty 

 river, and it was not until near the base of the Rocky Mountains, and after 

 one thousand miles of traveling acros.s it, that this great region of coal-beds 

 and lignites was passed." 



"On the return. Captain Clarke descended the Yellowstone from about 

 north latitude 45° to its mouth, 48° 20', and everywhere found the same 

 series of coal and variously colored clays and soft sandstones as was traversed 

 in ascending the Missouri. Below the Big Horn is a large stream falling in 

 from the south, whose Indian name implies the Coal Creek, from the great 

 quantity of this mineral upon its border. The same coal series continued to 

 the confluence of the Missouri, exhibiting uninterruptedly for seven hundred 

 miles, in addition to the thousand previously traversed, the vast persistence of 

 this formation. The enormous area of similar strata is further shown by 

 the decoloration of all the tributaries that enter the Missouri from both the 

 south and the north, from the forty-second to the forty-ninth degree of north 

 latitude." 



It is from the records of those celebrated explorers especially, also from 

 those of Audubon and Harris, Sublette, Fremont, Emory, etc., for the United 

 States, from the explorations in British America by Dr. Richardson, Drum- 

 moud, and Captain Franklin, that Taylor obtained the data for the delineation 



