It was too cold to enjoy our pipes, and we all bundled up for the night’s rest. In a few moments I heard the trapper’s deep breathing, and shortly after Nat joined him in sleep. But I found it impossible to get to sleep myself. The ground was so cold that my blanket could not protect me, and the cutting wind was terrible. I used every means that I could devise, but it was of no use, and I feared I should be compelled to either build the fire again, or to continue walking all night to prevent freezing to death. I chose the latter expedient. It was quite dark, yet I had noticed our situation well enough, I judged, not to lose it. So grasping my blanket in my hand, I started on a rapid run directly over the prairie. I continued a long distance, until pretty well exhausted. I turned to retrace my steps. My blood was warming with the exercise, and I hurried forward, counting upon sound sleep for the remainder of the night. I continued my run for a full half hour, and then stopped in amazement, as I saw no signs of my companions. Thinking I must have passed the spot where they were lying, I carefully walked back again, but still without discovering the men. I had lost them in the darkness, and it was useless to hunt them at night. So I concluded to wait till morning, feeling sure that they could be at no great distance. I now commenced searching for a suitable place for myself, and at last hit upon a small depression in the prairie. There was a large stone imbedded in the earth on one side, which served to protect me from the chilling wind. As I nestled down, beside this, such a feeling of warmth and comfort came over me that I congratulated myself upon what at first seemed a misfortune. Lying thus, just on the verge of sleep, my nerves painfully alive to the slightest sound, I suddenly felt a trembling of the ground. At first it seemed a dream; but, as I became fully awake, I started in terror and listened. I raised my head, but heard no sound, and still in the most perplexing wonder sank down again, hoping it would shortly cease. But there was a steady, regular increase, and presently I distinguished millions of faint tremblings, like the distant mutterings of thunder. Gradually these grew plainer and more distinct, and finally I could distinguish sounds like the tread of innumerable feet upon the prairie. Still at a loss to account for this strange occurrence, I listened, every nerve in my body strung to its highest tension. Still louder and louder grew the approaching thunder, and every second the jar of the earth became more perceptible. Suddenly the truth flashed upon me--_a herd of buffaloes were approaching_.