Rhythmic continental sequences characterize the proximal Genesee Group (Upper Devonian) in southeastern New York, which are interpreted as the remnant elements of a sequence of coastal-plain and upland fluvial deposits. A rhythm consists of a braided pattern of coarse conglomeratic channel-fill, a composite of point-bar, channel-fill, and overbank sandstones, and overbank, mudflat, and general flood plain accumulations of siltstones and mudrocks. Widespread lateral variability, rapid vertical change, channel depths of more than 30 feet, and textural mapping suggest a significant fall-line scarp close to the east of the present outcrop limit. Various aspects of the natural rhythmic sequences of the Genesee Group have been synthesized and examined using simulation techniques.