Out of the Depths by Robert Ames Bennet — Read

At dawn Blake and Ashton drove up to the waterhole on Dry Fork with their camp equipment. There they left the outfit in the buckboard and proceeded with the line of levels on up the creek bed into the gorge from which it issued.

For more than a mile they carried the levels over the bowlders of the gradually sloping bottom of that stupendous gash in the mountain side. So far the work was fairly easy. At last, however, they came to the place where the bed of the gulch suddenly tilted upward at a sharp angle and climbed the tremendous heights to the top of High Mesa in sheer ascents and cliff-like ledges. Blake established a bench-mark at the foot of the acclivity, and came forward beside Ashton to peer up the Titanic chute between the dizzy precipices. From where they stood to the head of the gulch was fully four thousand feet.