A novel high-resolution high-frequency range magnetotelluric (HFMT) survey was conducted to image an intertidal succession in a macrotidal environment. In Gomso Bay of the southwestern coast of Korea, HFMT data were collected on a line (∼1 km) comprising 21 recording sites at 50 m intervals. A two-dimensional section was constructed from the transverse magnetic (TM) mode, inspected by electromagnetic array profiling (EMAP) filtering and one-dimensional Bostick inversion. The image is demarked by two distinct discontinuities. The lower one is interpreted as a boundary between the basement of high resistivity and the overlying tidal deposits of low resistivity. The upper one is expected to be a significant layer of relatively high resistivity within low resistivity deposits. This is suggestive of nonmarine/tidal strata experiencing prolonged subaerial exposures within tidal successions. In a tidal-flat environment, the HFMT probing seems to effectively configure boundaries between the basement and successions of different physical properties.