"Whoa! What's wrong with you fellows?" demanded Tad, eyeing the ponies keenly. "Smell something, eh?"
"Maybe they smell oats," suggested Walter.
"I guess not. They are a long way from oats at the present moment."
Tad paused abruptly. A pebble had rattled down the rocky wall and bounded off some yards to the front of them. Silver Face started and would have bounded away had not a firm hand been at that instant laid on the bridle rein.
To one unaccustomed to the mountains the incident might have passed unnoticed. By this time Tad Butler was a pretty keen woodsman as well as plainsman. He had learned to take notice of everything. Even the most trivial signs hold a meaning all their own for the man who habitually lives close to Nature.
The lad glanced sharply at the rocks.
"See anything?" asked Walter.
"No."
"What did you think you heard?"
"I didn't hear anything but that pebble. The horses smelled something, though."