“Uh-huh,” said Garth. “You hear a heap nowadays about what the dry air’ll do for them lungers, but the health boosters tell only half o’ the story. That same old thin air kills ’em swift if they come too late. It shore do.”

By pushing the animals as fast as the hazardous trail would permit, the ranch in the inter-mountain park was reached in the shank of the afternoon. Philip made a hurried bargain with the ranch owner, a white-haired, white-bearded old man who might have figured as a reincarnation of Elijah the Tishbite; and after a consultation with Garth, refused the old man’s offer of a night’s lodging. Garth’s vote was for an immediate return to the “Little Jean.” The skies were clear and there would be a moon for at least the first half of the night.

“We’ve left a trail in the snow that a blind man could back-track on,” he pointed out. “I’m hep for the night tramp, if so be you are.”

Stiff from the long day in the saddle, Philip would have welcomed a blanket bed before the Tishbite’s hearth fire, but the urgencies were still acutely upon him; also, he was beginning to acquire the pride of the outdoor man. If Garth, who had already tramped miles before the afternoon meeting on the high pass, could stand it to keep on going, surely he could.

“We’ll tackle it,” he said shortly; and presently they were taking the steep mountain trail in reverse, slipping and sliding in the dry snow, but doggedly making their way toward the high, wind-swept pass.

Visioning that long night tramp in the moonlight, afterward, Philip knew it would be an enduring memory after many other experiences had faded and gone. The slippery trail; the black shadows of the trees while they were still in the foresting, and the blacker shadows of great rocks and gulch cliffs after they had climbed above timber line; the keen night wind sweeping over the bleak pass where they paused for a short halt in the lee of a sheltering boulder to eat a few mouthfuls of food before hitting the downward trail; the perilous descent to the headwater gulches of the Roaring Fork, where more than once he owed his escape from a sudden plunge into unknown depths to the quick clutch of the silent giant plodding along tirelessly behind him—no detail of the deadening, soul-harrowing fight for endurance, lapsing finally into a sheer effort of the will to thrust one foot before the other, would ever be forgotten.

The moon had long since disappeared behind the uplifted skyline of the western ranges by the time they were measuring the last of the weary miles in the valley of the lucky strike. At the foot of one of the jutting mountain spurs, Philip broke the slogging monotony to say: “We’re almost there. The next gulch is ours.”

“Good enough,” was the muttered comment from the rear; and then, suddenly: “Hold up—hold your hosses a minute!”

Philip turned and saw Garth stooping with his rifle held in the crook of an arm. He was peering down at the hoof tracks they had been following.

“What is it?” he asked.