A crumbled corner of the shelf gave them a steep slide, down which without a second’s hesitation Big John plunged. Whizz! Ankle-deep in red earth, accompanied by a cloud of big and little stones, he shot down the slope. Scotty followed, giving himself no time to let his imagination work. They tore on after the hounds, through thick, bushy pines and spruces that covered the slope. Without any warning at all, save the interminable blue distance ahead, it suddenly ended in another frightful precipice. Scotty brought up on the brink of it, hugging a sapling and glad to see that for once Big John had stopped. Over to the right the trees trailed down to a point, terminated by a tall red cliff, craggy-faced, indented with great slabs and bowlders, which threw huge shadows of themselves on the next cliff beyond. A sort of chasm or chimney led down its side, a mighty cleft full of bowlders in which all the skyscrapers in the world could be piled and never be found. Down this impossible, preposterous thing the dogs were climbing, as their voices proclaimed. Scotty looked up. Already the entire world seemed to have been stood up on end above him. The green pines and yellow pinnacles of the rim above looked like a line of mere dents in it, with a little dark moss covering their tops. It would be days and days of work getting up there again! But Big John had only paused to get the location of the dogs in mind before he set off again along that precipice wall. Scotty followed. He might as well be killed sticking close to Big John as be killed anyhow, by some fall which could only end up in the Colorado itself, perhaps half a mile yet below him in a vertical line! Ruler had charged out of the bottom of the chimney, barking a regular hullabaloo of a treeing call. If the dogs had slid down this cleft, men could climb down it, the boy reasoned as he began descending an almost perpendicular chimney, hanging to small, stout pines and catching his toes in crevices in the rock. They came upon Lee, whining piteously, afraid of being left behind, afraid to make the jump that would land in a sort of chute already worn with dog and cougar tracks where the others had gone down. Big John picked him up unceremoniously and tossed him into the chute, where he sprawled and slid with lightning speed down to the slope below. Without a word the man climbed on down after him, with Scotty panting and laboring behind. Once on the slope below a columnar yellow pine loomed up far down the slide. It had survived avalanches, rock slides, ice rifts--was Nature’s survival of the fittest, to seed the slopes beneath it and below it. Upon one of its branches the tawny body of the cougar crouched, treed, spitting at the dogs prancing below, twitching his tail angrily, ready to spring on the instant.