The petroglyphs are found upon the face of a sandstone cliff in a deep ravine at a point where two watercourses (dry for the most part), meet about 20 miles south of Sioux City, Iowa, but in Dakota county, in the State of Nebraska. At this point the range of bluffs which bounds the Missouri river bottom is deeply cut through by the above-mentioned ravine, which runs in a northerly direction towards the Missouri. Another ravine coming from the southwest leaves this narrow point of land between the two ravines, rising to a height of 50 to 75 feet above the bottom of the ravines. For some distance from the point this cape, if I may so term it, shows ledges of sandstone cropping out on both sides. And exactly at the point and for some rods back on the east side are found the pictographs under consideration. The rocks are of two kinds, a few feet of hard jasperous sandstone superimposed on about the same thickness of sandstone so soft that it can be crumbled to pieces in the fingers. The lower soft strata have been worn away, leaving the upper harder layers jutting out to a distance of several feet over and completely sheltering them. And on the smooth surface of these lower soft strata, protected by the overhanging ledge above, shut in by bluffs 200 feet high on the east and sheltered from the winds by dense underwood and scrubby forest trees, are carved these pictographs. These safeguards, combined with the advantage of a very secluded situation, have combined to preserve them, very little marred by careless and mischievous hands. The eagle or “thunder-bird” figures are quite numerous. There are also many of the “buffalo track” and of the “turkey track” figures. I call them “turkey tracks” because they all show a spur and seem to represent some of the large _gallinaciæ_. In one of the groups, which I will call the “bear-fight group,” we are at a loss to determine whether the figure of the small animal was a part of the original design or a subsequent interpolation. It seemed genuine, but was not so deeply carved as the other figures. The same may be said of the diagonal bars across the figure of the bear. In the other group, which I will term the “turkey-track group,” there are some figures of which we could not even imagine the meaning. But they are undoubtedly genuine, and seem to belong to the same design as the other figure. The “bear-track” figures are very numerous and of several different sizes. A cat-like figure, which we call a panther, shows faintly. It is about effaced by time. Other figures reminded us of a crab or crawfish, but we were unable to determine whether the line running back just below belongs to it or not.