Way of the Lawless by Max Brand

He had to be guided by what Uncle Jasper had often described -- a mountain whose crest was split like the crown of a hat divided sharply by a knife, and the twin peaks were like the ears of a mule, except that they came together at the base. By the position of those distant summits he knew that he was in the ravine leading to the cabin of Hank Rainer, the trapper.

Presently the sun flashed on a white cliff, a definite landmark by which Uncle Jasper had directed him, so Andrew turned out of his path on the eastern side of the gully and rode across the ravine. The slope was steep on either side, covered with rocks, thick with slides of loose pebbles and sand. His horse, accustomed to a more open country, was continually at fault. He did not like his work, and kept tossing his ugly head and champing the bit as they went down to the river bottom.