He flung away his rifle, that it might not impede his flight, and concentrated all his energies into the one effort of running.
He had no time to look where he was going.

He could only strive with the desperation of despair to preserve the distance between him and his pursuer, in the faint hope that something would intervene to save him.
Fred was not only firing his gun as fast as he could, but he shouted to the bear, in the hope of diverting his attention from Jack, who could not keep up the unequal flight much longer.
The terrified fugitive leaped over boulders, dashed around interposing rocks, and bounded across open spaces, hardly daring to look over his shoulder, for he knew from the sounds of pursuit that the animal was at his heels.

It seemed every moment as if the prodigious paw of the grizzly would smite him to the earth, when no human power could save him.
Suddenly the fugitive, while dashing forward in this blind, headlong fashion, found himself confronted by the canyon with which he and Fred had already had a memorable experience.

It yawned at right angles to the course he was following, its width so great that it was impossible for him to leap it at that point.

But he knew there must be some such place, and he continued his flight along the side of the chasm, hunting for a spot that would permit him to reach the other bank.
He did not stop to think how this could benefit him, for it was to be supposed that if the grizzly could outrun he could also outleap him, and the moment the fugitive landed on the further bank the brute would do the same, without losing an inch of the advantage already gained.