Stratigraphic cross sections and correlation of lignites in the Sentinel Butte member and upper part of the Tongue River member of the Fort Union Formation between Amidon and Fryburg, North Dakota

The Austin Farm bed was once mined form an adit in the SE1/4 sec, T. 136 N., R. 101 W. Its westerly outcrop extends from that point northward along the east side and north end of the valley of Third Creek at elevations between about 2740 and 2800 ft. It is the uppermost lignite bed preserved on Hanley and Cliffs Plateaus in T. 137 N., R. 101 W., where its thickness is generally from 2 to 4 ft. It is exposed at the NW corner of sec. 26, T. 138 N., R. 101 W., where it is 0.7 ft thick. The surface trace of the Austin Farm bed has not been mapped north of that location, and because of its thinness and local absence it is probably rarely exposed at the surface north of that point.