"Why, professor!" exclaimed Jack. "Is it not possible that it was to this river that those drawings of boats that interested and puzzled you so much had reference?"
"Quite possible, my boy," agreed the man of science.
"I wish we could find some way of getting down into it," said Ralph wistfully, poking at the ground, as if he thought he might force an entrance that way.
"Thar you go," laughed Pete. "Giv' you boys a cayuse, an' you'll ride him to death. I jes' mentioned that a lying, whisky-drinking old Injun had sprung a pipe-dream about a lost river, and thar you go navagatin' it in a Coney Island steamboat."
The boys could not help bursting into a laugh at the cow-puncher's whimsical way of talking. The professor joined in, too, for none realized better than he did that for a moment he, too, had been quite carried away by the idea.
"I expect that it is as you say, Pete," he agreed. "These Indians are most unreliable people. If anybody was to believe all the weird legends an Indian tells him, he would spend the best part of his life on wild-goose chases. Why, the Indians of the Mojave desert in California can even tell a circumstantial story about a buried city of Mojave. According to their contention, a great flood, occurring long ago, wiped it out and buried it in the sands of the desert."
"Has any one ever tried to find it?" asked Jack.
"Many expeditions have been fitted out for the purpose, my boy," was the rejoinder, "but so far no trace has ever been found of it, and it is, no doubt, like the lost river of which Pete was telling us, a mere myth."
"I didn't say it was a miff," protested Pete. "I jes' said I didn't believe it."
The remainder of that afternoon was spent in making more measurements and sketches of the interesting mesa, and the boys, on their own account, conducted a search for a possible entrance to the lost river. But, as may be supposed, they found none.