"Just            below [Henry's Fork] we entered the mouth of the first canyon and encamped            amid the cottonwood trees surrounded by bluffs 1200 ft. high and on            one side nearly perpendicular. It is the grandest scenery I have found            in the mountains and I am delighted with it. . . . The river winds like            a serpent through . . . nearly perpendicular cliffs . . . but instead            of rapids it is deep and calm as a lake." George Bradley, one of John Wesley Powell's 1869 crew, was not the first, nor would he be the last,            to be impressed with the canyons of the upper Green River. About sixty            river miles below the town of Green River, Wyoming, the Green entered            a series of canyons that were of rare beauty, and yet were largely unknown            except to Indians, outlaws, and river runners.