"Micas Falls," replied the agent.
"And the river?"
"It's called the Santa Rosa."
"Where does it go?"
The agent did not know, except that it disappeared in the jungle. Southward the country was wild. The villages were few and all along the railroad; and at Valles the river swung away to the southwest.
"But it must flow into the Panuco River," said Ken. He had studied maps of Mexico and had learned all that it was possible to learn before he undertook the journey.
"Why, yes, it must find the Panuco somewhere down over the mountain," answered the agent.
"Then there are rapids in this little river?" asked Ken, in growing interest.
"Well, I guess. It's all rapids."
"How far to Tampico by rail?" went on Ken.