Sea ice is a heterogeneous material whose acoustic properties are functions of time and space. Results of a crosshole tomography experiment conducted in multi‐year ice with the objective of determining the spatial structure of the compressional and shear wave speeds from travel time measurements made with high‐frequency pulses are presented here. The results of the experiment indicate that the wave speeds can be determined from such a crosshole experiment with good resolution. The compressional and shear wave speed contour maps indicate that the spatial variations of the wave speeds are complex with regions of low speed. Low‐speed regions observed are likely caused by high brine volume content. Resolution and variance studies performed on the estimates are also presented. Material properties such as Poisson’s ratio, salinity, and elastic and shear moduli of sea ice are obtained from the estimates of compressional and shear wave speeds. By measuring the amplitude of the transmitted and received signals alo...