This was drier and more gravelly than the other. While the soil seemed to have been disturbed, they could not make sure whether or not it was by the hoofs of an animal, but Frank caught sight of something on a projecting point of a rock, just in front. Stepping forward, he plucked it off, and held it up in the light. It consisted of a dozen dark, coarse hairs.
"That's where the burro scraped against the rock," he said. "We are on their path."
In their eagerness they would have kept beside each other had not the passage been so narrow. Often they came to places where one would have declared it impossible for a mule or donkey to make his way, but there could be no question that the property of Jeff Graham had done it. Frequently he slipped, and must have come near falling, but he managed to keep forward with his precious load.
Less than two hundred yards distant the pursuers came to a depression of the soil where it was damp, and the footprints of the donkey and the two men were as distinct as if made in putty. There could be no question that the boys were on the trail of the despoilers.
As they advanced, Frank, who was in advance; frequently turned his head and spoke in guarded tones over his shoulder to his cousin.
"They are pushing into the mountains," said he, "but there's no saying how far they are ahead of us."
"No; if they made the start early in the morning, it would give them a big advantage."
"I believe that is what they did, knowing there was no danger of our returning until night."
"That knowledge may have made them slow. Anyhow, they are not travelling as fast as we, and we must overtake them before long."
A few minutes later Frank asked: