" A valley that had some of the characteristics of a canyon yawned beneath, so deep and wide that it appeared like a blue lake, so long that he could only see the north end, which notched under a rugged mountain slope, green and black and golden and white according to the successive steps toward the heights. The height upon which he stood was the last of the ridges, for the elevation that lay directly across was a noble range of foothills, timbered, canyoned, apparently insurmountable for horses. Gray cliffs stood out of the green, crags of yellow rock mounted like castles. "

― Zane Grey , Valley of Wild Horses