THE PLT FAILED TO VISUALLY CHECK THE FUEL TANKS DURING PREFLT AND DEPARTED WITH 3.4 HOURS FLOWN ON THE PRE-EXISTING FUEL SUPPLY. FUEL EXHAUSTION OCCURRED 1.2 HOURS INTO THE FLT. THE PLT OVERFLEW A SUITABLE FORCED LANDING SITE AND ATTEMPTED A LAST MINUTE TURN BACK TO THE SITE. THE ACFT STALLED IN A STEEP TURN AT LOW ALT, COLLIDING WITH TREES ON A STEEP DOWNSLOPE. INSPECTION OF THE ACFT FAILED TO DISCLOSE SIGNS OF FUEL BOTH IN THE ACFT AND ON THE TERRAIN SURROUNDINGTHE WRECKAGE. THE FUEL GAGES WERE KNOWN TO BE INACCURATE AND THE OPERATOR HAD A SIGN POSTED INSTRUCTING PLTS TO VISUALLYCHECK THE FUEL QUANTITY. ALSO, A SEPARATE FUEL CONSUMPTION LOG WAS KEPT FOR THE ACFT. THE REAR BENCH SEAT HAD THREE OCCUPANTS SEATED ON IT WITH ONE SEAT BELT UTILIZED FOR ALL THREE. THE BELT SEPARATED FROM THE FLOOR MOUNTS DURING THE ACCIDENT.