An unreversed seismic refraction profile was obtained during the winter of 1966-1967 from several small chemical explosions in an open pit coal mine near Suntrana, Alaska. The profile runs from south to north across the Tanana Basin in central interior Alaska. Both P and S waves, generated by the explosions, were observed out to a distance of 217 km from the shot point. A four-layer crustal model is adopted to explain the first and later prominent seismic phases. The P velocities range from 3.67 km/sec in the sedimentary surface layer to an apparent value of 8.83 km/sec in the upper mantle. It is assumed that the Moho is dipping to the south under the Alaska Range, from a depth of 32 km at Fairbanks to approximately 48 km under the shot point.