"Hold on there! Who are you and where are you going?"
At the same moment his cousins saw the moon gleaming on the .45 gun which Bud drew from his holster.
CHAPTER II
A CURIOUS INSTRUMENT
"What's the matter, Bud?" asked Dick, as he urged his animal forward in a jump, until he was beside his cousin.
"Some one's up there around the tunnel entrance," responded Bud Merkel. "I saw 'em dodge back out of the light." Then, raising his voice, he cried: "Come on, now! None of your tricks! I've got you covered!"
"I don't see any one," spoke Nort.
"They're there, all right," asserted Bud. "Come on, fellows," he exclaimed, "we'll have to look into this. There was trouble enough with getting water to stay in Happy Valley, without letting some Greaser in to queer the works again! Come on!"
He and his cousins rode their horses up the rather steep and winding trail that led from the bottom of the reservoir to the top, where a big iron pipe, sticking out under the mountain like the head of some great serpent, brought from the distant Pocut River a stream, without which it would have been impossible to raise cattle in the valley the boy ranchers claimed as particularly their own.
"Who you reckon it is?" asked Nort, as his pony scrambled up between the animals of Dick and Bud.