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Show 58 FROM FORT LARAMIE TO FORT BRIDGER. morning has been about parallel with the range of the Black Hills, the base of which could frequently be seen from the more elevated portions of the road. The valley of the Platte also was to be seen far in the distance to the north. Grossing La Bontl Greek, encamped near a fine spring, after a fatiguing march of twenty-four miles. In passing along the ridge, the only rock exposed consisted of coarse sandstone, with a decided dip to the north- east of 15°, and beds of clay were interposed between the strata. On descending from the ridge into the valley of the fork, some siliceous limestone was found, from which a few fossils were collected. In the same locality were masses of sandstone of a reddish colour. On the side of a ravine to the left of the road, the same sandstone appeared to crop out. After crossing this stream, the geological character of the country changed materially. The soil assumed a red colour, being composed principally of red sandstones and shales. To the left rose a high crest or ridge crowned with gray and red sandstone, which was very hard. The general direction of this ridge was N. N. W. and S. S. E., and it was manifestly formed by the upheaving of the strata, the dip being at least 45° to the north- east, while the south- west face of the rocks was very precipitous. At nearly the highest point of the ridge, a small ravine occurred, containing a layer of coal shale, apparently overlaid by dark shales, and layers of red clay and light slaty shales. The portions of these strata which were exposed were in so decomposed a state that no fossils could be obtained except very imperfect ones. In the valley of La Bont£ Creek, the soil was found to be formed by the decomposition of highly ferruginous rock. Before the crossing of this stream, a ravine exposed a layer of gypsum, which was very fine and white, and of considerable thickness. Overlying it were layers of red sandstone and shales, conformable with the apparent dip of the sandstones forming the crest. A mile or two beyond the La Bont£, the gray sandstone was seen cropping out, overlying the red sandstone, and with a considerable dip to the north. Above these were layers of red and light shales and impure carboniferous limestone, from which a number of fossils ( Avicula monotis, and Cardinia) were collected. The limestone seemed to be composed, to a great extent, of shells: in the more sandy and slaty shales the fossils were not so numerous. To the left were some eminences composed of the more resisting sand- |