The rocks rose perpendicularly on both sides to the height of fifty and a hundred feet, the upper contour being irregular, and varying in every manner imaginable.  Along the upper edge of the pass grew vegetation, while here and there, along the side, some tree managed to obtain a precarious foothold, and sprouted forth toward the sun.  The floor of the canon was of a varied nature—­rocks, boulders, grass, streams of water, gravel, sand, and barren soil, alternating with each other and preventing anything like an accurate description of any particular section.  A survey of this curious specimen of nature’s highway suggested the idea that the solid mountain had been rent for many leagues by an earthquake, which, having opened this great seam or rent, had left it gradually to adjust itself to the changed order of things, and to be availed of by those who were seeking a safe and speedy transit through the almost impassable mountains.

Mickey and Fred checked their mustangs and carefully scrutinized the line of smoke.  It was several hundred yards in advance, on their left, while they were following a trail that led close to the right of the canon.  They could distinguish nothing at all that could give any additional information.

The fire which gave rise to the vapor had been kindled just far enough back to cause the edge of the gorge to protrude itself in such a way as to shut it off from the eyes of those below.  Indeed, it was not to be supposed that those who had the matter in charge would commit any oversight which would reveal themselves or their purpose to those from whom they desired to keep them.

“That is the same as the camp-fire which troubled the three Apaches so much, and which was the means of my giving them the slip.”

“It must have been started by some other war-party, so that their ca’c’lations were upsit, and you had a chance to get away during the muss.  It was a sort of free fight, you see, in which, instead of staying and getting your head cracked, you stepped down and lift.”

Unable to make anything of this particular signal-fire, the two friends carefully searched for more.  Had they been able to discover one in the rear, they would have been assured that signaling was going on, and they would not have dared to venture forward.  Here and there along the sides of the canon were openings or crevices, generally filled with some sort of a vegetable growth, and into most of which quite a number of men could have taken refuge, but which, of course, were inaccessible to their horses.

“I can’t find anything that resimbles the same,” said Mickey, alluding to the camp-fire, “though there may be some one that is seen by the gintlemen who are cooking their shins by yon one.”

“Will it do to go on?”

“It won’t do to do anything else.  Like enough the spalpeen yonder has obsarved us coming, and he knows that there’s a party behind us, and, being unable to do anything himsilf, he starts up the fire so as to scare us, and turn us back into the hands of the spalpeens coming in our rear.  Mind, I say that such may be the case, but I ain’t sure that it is.”