GEOLOGICAL SURVEY OF THE TERRITORIES. 359 



5 feet each in thickness, and occurring at various elevations above the river. At fifty 

 miles above the village, similar coal-seams were noted, but here they were observed to 

 be on fire, emitting quantity of smoke, and a strong sulphurous smell. Further on the 

 same sulphurca.is coal continued for eighty miles more ; strata of coal, frequently in a 

 state of combustion, appearing ju all the exposed faces of the bluffs. The quality of 

 the coal improved as the party advanced near the mouth of the White River, eighty- 

 five miles farther, alfording a hot and lasting tire, but emitting very little smoke or 

 flame. Thence forty-seven miles to the Yellowstone River, and at a bluff eight miles 

 up that stream, were several strata of coal. For fifty miles above the junction of the 

 Yellowstone and the Missouri there were greater appearances of coal than had yet been 

 seen, the seams being in some places 6 feet thick, and there were also strata of burnt 

 earth, which were always on the same level with those of coal. The explorers had 

 thus far traced this lignite formation along the banks of the Missouri for a distance of 

 three hundred and thirty miles. The horizontal formation of clay, loam, and saud, 

 with fragments of coal in the drift of the river, extended three hundred miles more co 

 Muscle-shell River, or sis hundred and twenty miles from the Mandau 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 jjreviously 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, northward, 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 winding 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 across it, that this great region 

 of coal-beds and lignites was passed. 



On his return Captain Clarke descended the Yellowstone from about north latitude 

 45^ to its mouth, 4b° '20', and everywhere found the same series of coal, and variously 

 colored clays ancl 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 uninter- 

 ruptedly 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.* 



In 1832 Prince Maximilian, of Neuwied, passed up the Missouri Eiver, 

 and in the splendid record of his travels mentions the occurrence in 

 numerous localities of thick, beds of lignites. 



Some more detailed information on the distribution of the lignite-beds 

 of the Tertiary are given by Mr. E. Harris,t who accompanied Audubon 

 up the Missouri to the mouth of the Yellowstone, in 1843. He counted, 

 at one place, eight seams of coal between the river and the top of the 

 bluff, their thickness varying fi^om 6 inches to 4 feet. 



In Dr. D. D. Owen's final report of a geological survey of Wisconsin, 

 Iowa, and Minnesota, an account is given of Dr. John Evan's exploration 

 of the Mauvaises Terres. He remarks, (p. 195 :) 



That below Fort Clarke the great lignitic formation first shows itself in the banks of 

 the Missouri. It was traced to a point twenty miles below the Yellowstone. One of 

 the thickest and most valuable beds of coal observed by Mr. Evans occurs near Fort 

 Berthold, where it is from 4 to 6 feet thick. 



In 18.50 Mr. Thaddeus A. Culbertson vivsited the Upper Missouri to 

 above Fort Union, noting the occurrence of lignite-beds at various 

 localities. 



Thus, at different times, the lignite-beds of the Upper Missouri and 



* R. C. Taylor, Statistics of Coal, p. 17.5. 



t In Proceedings of the Acad, of Nat. Sci., Phil.j May, 1845. 



