The Frontier Boys in the Grand Canyon

"Your cayuse is quiet as a lamb now, isn't he, Jo," inquired Jim.
"He ought to be by this time," I replied. "You wouldn't expect him to buck all the way through New Mexico, I hope."
"It's funny how he began to act up," remarked Tom, "just as soon as we got out of Colorado."
"Maybe he doesn't like getting away from the country of his own tribe," I said; "He's a regular little Injun I can tell you that."
"I can't blame him for his dislike for the Apache range," interposed Captain Graves, "for...