The East River, New York, is a cooscillating tidal strait connecting New York Harbor to western Long Island Sound. Linear wave theory is applied to the river in an attempt to interpret the tidal characteristics. The theory accurately describes the observed longitudinal variation in amplitude of the tidal current, but the simple model used does not adequately predict the amplitudes of the tidal heights or the overtides. The frictional resistance to flow through the river is characterized by an effect value of De Chezy's coefficient of ~26 m1/2s-1. Tidal current records gathered over a 5-day period from a linear array placed across the Upper East River have been analyzed to investigate the harmonic content of the tidal transport. The semidiurnal frequency and its third harmonic (M6) are dominant.