NTSB Probable Cause

THE PILOT'S FAILURE TO MAINTAIN ADEQUATE ALTITUDE WHILE MANEUVERING IN MOUNTAINOUS TERRAIN WHICH RESULTED IN GETTING TRAPPED IN A BOX CANYON, RESULTING IN A STALL DUE TO INADEQUATE AIRSPEED. FACTORS WHICH CONTRIBUTED TO THE ACCIDENT WERE: THE PILOT'S DECISION TO FLY INTO MOUNTAINOUS TERRAIN AT A LOW ALTITUDE, HIS IMPAIRMENT DUE TO DRUGS, AND THE TERRAIN CONDITIONS.