Publisher's Synopsis
One of Zane Grey's Ken Ward series of books for boys. A great adventure read from the great author of Western fiction. Ken Ward and his younger brother Hal take a trip into the wilds of Mexico; Ken to try his hand at field work in the jungle and Hal, who is ambitious to become a naturalist, to collect specimens. The boys set out to solve the mysteries of the Santa Rosa River, an unknown course of about a hundred and seventy-five miles through uncharted jungle.
