They were relaxing at the top of a waterfall, in a small, still pool where the mountain waters hit an upward slope of folded granite. It was sort of a rounded bathtub, carved out of the rock throughout the centuries by the rushing river, a river so hidden that it was without a name. Just below were the falls, about a 30-foot drop into another, much larger pool of clearest water that was gathered for a respite, a compromise in the river's relentless schedule downward, between split-level decks of flat rock. Further on, the river reanimated and released into a sharp ravine, pulling westward, down through the rugged mountains and faceless forest--the Black Hills National Forest--gaining force until it joined with the rush of the Castle River, near the old Custer Trail, and was swallowed into the Deerfield Reservoir to collect and prepare for the touch of man.