The bottom land, on the left bank, is still confined to a narrow strip. The sun having been, during the chief part of the day, obscured by an interrupted sheet of cirrostratus, and a brisk N. E. wind prevailing, rendered the day temperate and agreeable. Travelled distance miles nineteen and a half. Thursday, 17th. Having been entirely unsuccessful in hunting since the 13th instant, we remained in our position during the morning, and sent out four hunters to procure fresh meat; but towards noon they all returned with but three turkies, of which two were young; they saw no deer, but much elk sign. At two o'clock proceeded onward, upon a slightly undulated prairie, over which the eye roves to a great distance without impediment. Indeed the surface of the country, which extends along the upper portions of the Platte and Arkansa rivers, is generally less undulated than that which extends on either side of the Missouri. {82} The ravines which intersected our path were not so extensive or profound as those of yesterday, and in one of them we observed the common elder (sambucus). Should military possession ever be taken of this elevated country, eligible positions might readily be selected for military posts, at several different points below the Little Arkansa, where the bluffs almost impend over the river. Such a position was occupied by our evening encampment. This bluff is naked, of a gently rounded surface, presenting a high rugged and inaccessible front upon the river, which it commands to a considerable distance in both directions. An adequate supply of wood, for fuel and architectural purposes, is offered by a ravine, which flanks its lower side, and by other points. Two fawns were killed during this afternoon's journey of twelve miles, and a black bear was seen. The bitter apple vine occurred now but rarely. Friday, 18th. The inequality of the surface increases as we proceed, the undulations being now much more abrupt and considerable, belted near their summits with a rocky stratum, and assuming much the same character with those spoken of in the account of our expedition to the Konza village. This stratum, which is of gray and ferruginous sandstone, contains petrifactions of marine shells, so completely assimilated with the matrix in which they repose, and decomposing so entirely simultaneously with it, when exposed to atmospheric action, that even their generic characters cannot be recognised. Amongst other appearances, however, we observed a bivalve, which seemed to differ from terebratula and its congeners.