But this warning is imperative, as is that other of the fast westering sun; and when a movement on the opposite height gives him one more chance to announce volley-wise that the pass is still manned, he retreats swiftly, remounts after more than one exhaustive effort, and canters down the farther windings of the trail into a valley shut in on all sides by snow-coifed sentinel mountains, and with a brawling stream plunging through its midst; into this valley and down the length of it to a narrowing of the stream path, where a rude cabin, with its door hanging awry, looks across from the heel of the western cliff to the gray dump of a tunnel-opening in the opposite mountain side. The sun has already set for the lower slopes of the shut-in valley, and the frosty breath of the snow-capped sentinel peaks is in the air. At the door of the cabin the winner in the desperate race slides from the saddle. His knees are quaking, and because of them he stumbles and falls over the log doorstone, cursing his helplessness in the jolt of it. But there remains much to be done, and the sunset glories are changing from crimson and dusky gold on the snow-caps to royal purple in the shadow of the western cliff. With many slippings and stumblings he crosses the foot-log and climbs to the level of the tunnel-opening opposite, constraining the unwilling horse to follow. With a stone for a hammer he tacks a square of paper on one of the struts of the timbered entrance; and after another struggle feebly fierce the horse is dragged into the low-browed cavern and tethered out of harm's way. By the leaden-footed step of the man one would say that the last reserves of determination have been called in and are far spent; but he will not desist. With four stakes taken from the heap of wooden treenails used in the tunnel timbering he drags himself from corner to corner of the claim, pacing its boundaries and marking the points of intersection with dogged exactness. When the final stake is driven he can no longer stand upright, and is fain to win back to the tunnel on hands and knees with groans and futile tooth-gnashings. But the aftermath of the task still waits; shall wait until he has barricaded the tunnel's mouth with an up-piling of timbers, fragments of rock, odds and ends movable, with a counterscarp of loose earth to make it bullet-proof--the last scraped up with bleeding hands from the débris at the head of the dump.