We had not left the valley far when we came among the great sand-hills, which grew higher and softer until they were almost untraversable. Keeping in the vicinity of a small stream called Rock Creek, which courses its way among the bluffs, we traveled several days, keenly watching for anything that looked like meat. We never became careless, however, and the fire was always deadened before dark, while the wagon was placed upon some high spot for the night, in order to avoid the treachery that might be lurking behind the hills. Breaking our way through the soft, deep sand, we were compelled to travel very slowly. Sighting a single _buffalo_, upon one occasion, we fully expected to find a great herd behind every hill. That was the only one, however, that we got a glimpse of; and not having killed even a _rabbit_ since we left the river, and our horses becoming very much worried, we concluded to turn back. The many _skeletons_ that were scattered over the face of the country showed that the soft surface was not _always_ trackless, and that we were not the first hunters who had plowed the sands of that region. However, the great herds that we had expected to find had sought another range, and not even a wolf howled in the deep silence. We could but feel a little discouraged at so great a disappointment; and as we journeyed back toward the river, each mile was an effort. We reached the river again after a circuit in the sand-hills of just fourteen days; and during this time we had eaten nothing but flap-jacks. It is needless to say that we were hungry for _meat_, and there being many _cattle_ in the valley, we imagined the little calves to be buffaloes; and it was not long after sight, nor with much ceremony, that we were eating something that had not stuck in our teeth for two long weeks. After learning from an old hunter, whom we met on the prairie, that buffaloes journeyed north in the spring and south in the fall, we determined to follow them if they went to _South America_.