"Gone?" echoed Clark in an amazed tone.
"Yes, clean wiped out."
"But how?"
"Ask me an easy one."
"Hasn't he left a trail?"
"No, that's what makes it so queer. He must have had an aeroplane."
For half an hour or more both youths searched the dusty trail and beat in and out of the dense brush, but not a trace of the missing boy rewarded their close scrutiny of the surroundings. Had the earth opened at that spot and swallowed Rob up bodily, he could not have vanished more utterly. The only trace of the missing boy was his sombrero, lying by the dead pony.
Absolutely dumfounded with amazement, the two worthies finally gave up their search, and taking the saddle and bridle off the dead pony, made their way back to their camp, carrying Rob's broad-brimmed hat.
At about the same hour that Clark and Bill were searching among the piñon and scrub growth for some solution of the mystery of Rob's inexplicable disappearance, an equally perplexed party was assembled on a small rise some miles away. The latter group consisted of Mr. Harkness, his son, the Boy Scouts of the Ranger Patrol, Corporal Merritt Crawford and Tubby Hopkins, Blinky and two other cow-punchers.