We report on a detailed experimental investigation of lateral tunneling between electrodes of a two‐dimensional electron gas separated by the voltage‐controlled barrier of a nanometer Schottky gate. The experimental data are modeled using the WKB method to calculate the tunneling probability of electrons through a barrier whose shape is determined from a solution of the two‐dimensional Poisson equation. This model is in excellent agreement with the experimental data over a two order of magnitude range of current.