"This report presents the results of the post-burn evaluation of an underground coal gasification site near Centralia, Washington. This site was the location of CRIP UCG experiment. Two identical high resolution seismic surveys were performed. The first survey was performed in March, 1983, and gathered the data necessary to lay the ground work for later definition of the burn cavity. The second survey, performed following the burn, was done in February, 1984. The high resolution seismic data gathered was processed, and interpreted both to man the extent and depth f the coal, and to determine the shape and size of the underground burn cavity."