  We present measurements of momentum-resolved magneto-tunneling from a
perpendicular two-dimensional (2D) contact into integer quantum Hall (QH) edges
at a sharp edge potential created by cleaved edge overgrowth. Resonances in the
tunnel conductance correspond to coincidences of electronic states of the QH
edge and the 2D contact in energy-momentum space. With this dispersion relation
reflecting the potential distribution at the edge we can directly measure the
band bending at our cleaved edge under the influence of an external voltage
bias. At finite bias we observe significant deviations from the flat-band
condition in agreement with self-consistent calculations of the edge potential.
