"That's a water marker. When a traveler across the desert finds a sink he indicates it either by a heap of stones, which he sticks in the ground, or by any other means at his command. For instance, this pile of stones tells me there is a water hole somewhere near by, and the arm points the way to it."
"Where is it, then?" wondered Walter. "I don't see any signs of water."
"Nor do I. We'll follow the direction indicated by the arm and see if we don't come up with a water tank somewhere close by," replied Parry.
With the guide leading the way, the others following in single file, they trailed away to the westward until, finally, they came to a slight depression in the ground.
"It should be near here," the guide informed them. "There it is. See that dark hole?"
The boys bounded forward, dropping on their knees by the opening into which they peered inquiringly.
Suddenly they uttered a yell, and, springing up, ran back as fast as their legs would carry them. As they did so, some dark object bounded from the water tank and leaped away into the sage brush.
"Goodness me, what was that?" cried Walter, after the boys had pulled up and faced about.
"Come back, come back. That was only a badger," laughed the guide.
"In the water?" asked Tad, who had stood his ground.