The Bureau of Mines'Laramie Energy Research Center recently completed an underground coal gasification experiment at Hanna, Wyo., in a 30-ft-thick seam of subbituminous coal at a depth of 400 ft. The Hannah project, which produced a 125 Btu scf gas using the percolation method, experienced no leakage or difficulties in linking boreholes. Seam water, rather than posing a problem, appeared to be an asset. Calculation of the material balance based on the carbonization of coal indicated an energy recovery efficiency of 58%, a coal utilization efficiency of 63%, and an overall energy recovery efficiency of 37%--higher than any achieved in previous experiments for the length of time considered. A second experiment is currently under way to develop process control and evaluation techniques and evaluate the feasibility of using underground gasification to recover energy from coal seams considered unsuited for current mining techniques. This project uses an oxygen-blown system, an improved well linkage system, and in-situ instrumentation consisting of both active and passive acoustic techniques, surface and subsurface resistivity, and temperature and pressure measurements.