THE PILOT EXECUTED A STEEP, REDUCED POWER DESCENT INTO THE DESTINATION AIRSTRIP. HE THEN REPORTED THAT WHEN HE ATTEMPTED TO REDUCE THE RATE OF DESCENT WITH A POWER APPLICATION, THE ENGINE DID NOT RESPOND. THERE WAS NO EVIDENCE OF ANY MECHANICAL MALFUNCTION WITH THE POWERPLANT AND THERE WAS NO INDICATION THAT THE PILOT HAD APPLIED POWER NOR CLEARED THE ENGINE DURING THE DESCENT. THE LONG, POWER OFF DESCENT IS BELIEVED TO HAVE COLD SOAKED THE ENGINE RESULTING IN POOR ENGINE RESPONSE DURING THE RETURN OF POWER. THE PILOT'S FAILURE TO INSURE SUFFICIENT ALTITUDE AT THE COMMENCEMENT OF THE APPROACH AND/OR RAISE THE GEAR AFTER THE POWER LOSS RESULTED IN THE AIRCRAFT LANDING SHORT OF THE INTENDED RUNWAY. HIS UNFAMILIARITY WITH THE AIRSTRIP AND ITS ASSOCIATED MOUNTAINOUS TERRAIN AS WELL AS THE HIGH DENSITY ALTITUDE CONDITIONS CONTRIBUTED TO THE AIRCRAFT LANDING SHORT.