"Well, Dick," said I, "I still don't see why you should conclude that this is the trail of a pack-train. It seems to me much more likely to be due to water only. In the first place, though there is room enough and to spare on the ledge, your supposed trail is on the very outer edge, where a false step would send the burro head-first into the cañon; and in the next place, it keeps to the very edge, no matter whether the ledge is wide or narrow."
"That's exactly the point," explained Dick. "It is just that very thing which makes me feel so sure that this is the trail of a pack-train. You've never seen pack-burros at work in the mountains, have you? Well, I have lots of times: they are frequently used to carry ore down from the mines. If you had seen them, you could not have helped noticing the habit they have of walking on the outside of a ledge like this, where there is a precipice on one side and a cliff on the other. A burro may be a 'donkey,' but he understands his own business. He knows that if he touches his pack against the rock he will be knocked over the precipice, and he has learned his lesson so well that it makes no difference how wide the ledge may be—he will keep as far away from the rock as he can. As to a false step, that doesn't enter into his calculations: a burro doesn't make a false step—there is no surer-footed beast in existence, I should think, excepting, possibly, the mountain-sheep."
"I never thought of all that," said I. "Then I expect you are right, Dick, and this is an old trail after all. What is your idea? To follow it down, I suppose."
"Yes, certainly. Our animals won't make any bones about going down a wide path like this. They are all used to the mountains. So let us get them at once and start down."
Dick was right. Our horses, each led by the bridle, followed us without hesitation, while old Fritz, half a burro himself, took at once to the trail which one of his ancestors, perhaps, had helped to make.
Without trouble or mishap, we descended the steeply-pitching ledge down to the margin of the creek, crossed over to the other side, and continued on our way up stream over the slope of decomposed rock fallen from the towering cliff which rose at least a thousand feet above us—the cliff being now on our right hand and the stream on our left.
This sloping bank was scantily covered with trees, and among them we threaded our way, still following the trail, which, however, down here had lost any resemblance to a made road, and had become a mere thread, more like a disused cow-path than anything else.
Presently, we found that the cañon began to widen, and soon afterward the cliff along whose base we had been skirting, suddenly fell away to the right in a great sweeping curve, forming an immense natural amphitheatre, enclosing a good-sized stretch of grass-land, with willows and cottonwoods fringing the nearer bank of the stream.
As we sat on our horses surveying the scene, we found ourselves confronting at last the imposing north face of the mountain. Up toward its summit we could see the great semi-circular cliff which we supposed to be the upper half of an old crater, while the country below it, bare, rocky and much broken up, was exceedingly rough and precipitous.