name of Pawnee Rock. It is a yellow sandstone, overlaid and surrounded by ferruginous sandstone and the scoriaceous rock. The gradual transition of the ferruginous sandstone into the scoriaceous rock is here very distinct, and leaves no doubt as to the origin of the latter. Having no other light but the moonshine, T was not able to examine the surrounding hills closer. Late in the night we reached Ash creek; there was plenty of wood, but not a drop of water in the creek: it did not, however, prevent us from enjoying first some roasted hump-ribs, and then sleeping soundly in our blankets.
June 6.–Went in the morning but six miles, to Pawnee Fork. Near that place I discovered again yellow and red sandstone, uplifted, as it were, from southwest to northeast, by the scoriaceous rock. The ferruginous sandstone itself is here more compact, and deep red. Pawnee Fork is an excellent camp. The short buffalo grass is rather dry, as everywhere else now, but there is plenty of timber, and fine running water, containing fish. In the evening we loft again, and travelled through the same plain till late in the night. Having passed several dry creeks, we camped at last about 16 miles from Pawnee Fork, in the prairie, without wood and water, and with but tolerable grass. On the road we saw the grave of the unfortunate man who but a week ago had been killed by the Indians, as his companions, from Bent's Fort, had already told us.
June 7.–We reached in the morning Little Coon creek, (six miles,) and rested near a water pool. In the evening we travelled on; and finding no water in Big Coon creek, we camped again in the prairie, without water, (15 miles.) Although we travel yet through the same plain, with the Arkansas to our left, less and less buffaloes are seen every day.
June 8.–After a few miles march we found in the morning some standing water in a creek, probably a branch of Big Coon creek. The bluffs of the creek consist of common sandstone below, and a white, fine grained marl, without fossils, above it. This marl also resembles some specimens brought by Mr. Nicollet from the upper Missouri, and belonging to the cretaceous formation. Having refreshed our animals, we travelled in the forenoon 10 miles further, gradually ascending till we reached the Arkansas, and halted at noon. The Arkansas, like all prairie rivers, is rather monotonous and tiresome: broad, but shallow and sandy, with low bluffs or none at all, bordered sometimes with cotton trees, but generally quite bare, it hurries its waves rapidly through the open prairie, as if it were itself very anxious for a change. However, after having travelled for some 100 miles through the prairie, one is contented even with a less beautiful river, and considers it an improvement in the scenery. On the place of our noon halt I found low bluffs on the river, formed by a grayish limestone, with some very small and rather indistinct fossils, and granulated, like a fine conglomerate. In the afternoon we went about 12 miles up the river. The valley of the Arkansas is here several miles wide, the soil sandy, and the bluffs mere hills, covered with grass. Our night camp was on the "Caches;" so called from a party having, in 1822, hid their goods here. Near this place, it is understood, passes the hundredth degree of longitude west of Greenwich, but I had no chance to make an observation.
June 9.–Moved about 20 miles up the Arkansas; sometimes travelling in the valley, sometimes on the bluffs, and over a high plain into which they run out. The bluffs to-day were formed by a coarse conglomerate
