For several hundred yards the bluff could be climbed.

He took stock of those careless guards.

They had rifles, and that made vain any attempt to pass them in daylight.

He believed an attempt by night might be successful; and he was swiftly coming to a determination to hide there till dark and then try it, when the sudden yelping of a dog betrayed him to the guards on the bluff.
The dog had likely been placed there to give an alarm, and he was lustily true to his trust.

Duane saw the men run together and begin to talk excitedly and peer into the brake, which was a signal for him to slip away under the willows.