The trail leads down to a flat ledge which overlooks the desert, and which is the observatory whither countless generations of mountain-sheep have been wont to resort to survey the strange world beneath them--with what purpose and what feelings, it remains for some imaginative writer of animal-stories to inform us. From the ledge to the valley below the trail is free from obstructions, and broader, more beaten, and less devious than above, indicating that it has been formed by the generations of men toiling up from the valley to the natural watch-tower on the heights. Reaching the ledge, the prospector found that what seemed from the angle above to be an irregular pile of large boulders was an artificial fortification, the highest wall being toward the mountains. Entering the enclosure the prospector dismounted, relieved his horse of its saddle and his burro of its pack, and proceeded to prepare his midday meal. Looking for the best place where he might light a fire, he observed, in the most protected corner, a flat stone, marked by fire, and near it, in the rocky ground, a pot-hole, evidently formed for grinding maize.