As they came nearer to the dam the boys could see how well-made it was, and what a big piece of engineering it was to stop the flow of even a small river.
"Say, this is immense!" exclaimed Frank.
"I should say so," agreed Andy.
"There'll be a dandy lake here when the dam is completed, all right," said Billy.
"Won't it take a long time for the river to back up and fill all that valley?" asked the elder Racer lad.
"Oh, not so very long. If we get some good heavy rain, such as we sometimes have, or a cloudburst, it would almost fill up over night, providing the outlet gates were all closed."
The boys went nearer the dam to inspect it. The workmen had left, for there was nothing for them to do as long as the dam could not be completed. The land in dispute, which led to Golden Peak, was only about ten feet wide at the dam—a mere road, though it widened out as it approached the third hill.
There were several sluice-ways leading from the dam, with controlling gates, so that the water could be sent in many directions and to a number of ranches, as well as to almost every part of Mr. Thornton's land.
While the boys were looking at the irrigation works, they heard someone approaching from the inner side of the dam, and presently a voice hailed them.
"Oh, it's Uncle Richfield," said Billy, as he saw his relative approaching on his horse. "Did you see anything of them?" he asked.