THE AIRPLANE CRASHED ABOUT 2 MI SHORT OF THE DESTINATION ARPT. WITNESSES REPORTED THAT IT IMPACTED NOSE DOWN AFTER CLEARING TREES; NO ENGINE SOUNDS WERE HEARD. ACCORDING TO RESCUE PERSONNEL, THE PLT INDICATED THAT THERE WERE NO ENGINE OR OTHER MECHANICAL FAILURES; HE INDICATED INSTEAD THAT HE HAD A PROBLEM W/ FUEL. THE PERSONNEL NOTED THAT THEY DIDN'T SMELL ANY FUEL ODOR OR OBSERVE ANY FUEL SPILLAGE AT THE SCENE. EXAM OF THE ACFT REVEALED ONLY TRACE AMOUNTS OF FUEL IN THE ACFT FUEL SYSTEM. NO EVIDENCE OF FUEL CONTAMINATION OR MECH MALFUNCTION WAS FOUND. THE PLT HAD DEPARTED THE ARPT EARLIER IN THE DAY W/ APPROX 64 GAL OF FUEL ON BOARD. TOTAL CAPACITY IS 89 GAL. NO EVIDENCE WAS FOUND TO INDICATE THAT ADDITONAL FUEL WAS OBTAINED DURING SUBSEQUENT STOPS. INTERPOLATION OF ACFT PERFORMANCE CHARTS REVEALED THAT THE AIRPLANE HAD AN EXPECTED ENDURANCE OF ABOUT 4.7 HRS AT 65% PWR, WITH 64 GAL OF USABLE FUEL. THE ACTUAL ELAPSED FLT TIME SINCE REFUELING WAS ABOUT 5 HRS, BASED ON TACH TIME.