CROSSING OF THE SOUTH FORK OF THE PLATTE. 39 



dicular section of the rocks was seen in place. The bluff was in- 

 tersected by ravines, many of which also exposed vertical sections. 

 The strata were nearly horizontal, with perhaps a slight slip to the 

 west, and very fossiliferous, some of them being composed of en- 

 crinital remains. The hills were about one hundred and fifty feet 

 in height, and consisted of the following strata : — On the surface, a 

 yellow shale, containing encrinites and grit ; layers of loose detri- 

 tus and quartzose conglomerate ; brown shale and sand, the former 

 containing wood and bones ; white sandstone, the exposed surface 

 marked by ripples ; calcareous sandstone ; sandy limestone, com- 

 posed principally of remains of stems of encrinites, none of the 

 central portions of which were found, (this layer was some feet 

 thick, and was traced fully a mile ;) whitish sandstone ; botryoidal 

 limestone. The fossils found were the remains of encrinites, 

 which were abundantly diffused through the different strata, with 

 the exception of the detritus. Some bones occurred, but in a very 

 imperfect state : a large flat bone was found imbedded in sandy 

 shale, and endeavours were made to get it out, which did not suc- 

 ceed. The part exposed presented a segment of a circle from 

 twelve to sixteen inches in diameter. About half a mile below 

 this point was a peak formed by large masses of encrinital lime- 

 stone ; and at a point still lower down, the same formation was 

 found, the whole being crowned by a white marl, containing encri- 

 nites and grit. At this point were discovered the remains of the 

 bones of some large animal, only imperfect specimens of which 

 could be procured, for want of the means of extracting them. 

 One fragment was seen, fully seven inches in circumference ; and a 

 tooth, exposed for a length of five inches, was broken in the 

 attempt to get it out. The condyle of the jaw and what was sup- 

 posed to be the foot of some reptile were secured. 



Monday, July 2. — Ther. at sunrise, 68° ; Bar. 26.63. After tra- 

 velling up the river for fourteen miles, it was determined to make 

 the crossing of the South Fork by fording. In preparation for 

 this movement, one of the wagons, as an experimental pioneer, was 

 partially unloaded, by removing all articles liable to injury from 

 water, and then driven into the stream ; but it stuck fast, and the 

 ordinary team of six mules being found insufficient to haul it 

 through the water, four more were quickly attached, and the cross- 

 ing was made with perfect safety, and without wetting any thing. 

 In the same manner were all the remaining wagons crossed, one 

 by one, by doubling the teams, and employing the force of nearly 



