THE PLT HAD FLOWN FROM CARSON CITY, NV TO SHREVEPORT, LA ON 12/10/84 FOR BUSINESS. AT 1530 ON 12/12/84, HE DEPARTED ON AFLT TO CORONA,CA WITH REFUELING STOPS AT ALBUQUERQUE, NM & PHOENIX, AZ. HE DEPARTED PHOENIX AT 2100, BUT ENCOUNTERED WX & RETURNED TO PHOENIX WHERE HE REFUELED AGAIN & OBTAINED A LENGTHY WX BRIEFING. HE THEN ELECTED TO RETURN TO HIS HOMEARPT AT CARSON CITY & TOOK OFF AT 2351. WHEN THE ACFT DID NOT ARRIVE, A SEARCH WAS INITIATED. RADAR DATA REVEALED AN UNIDENTIFIED TARGET THAT DISAPPEARED NEAR GENOA, NV. DURING A SEARCH IN THAT AREA, THE WRECKAGE WAS FOUND WHERE THE ACFTHAD CRASHED NEAR THE TOP OF A MOUNTAIN ABOUT 5 MI NORTH OF THE PLT'S HOME. THE ELEVATION WAS APRX 9050 FT. IMPACT OCCURRED ON A WESTERLY HEADING, ABOUT 2 HRS BEFORE MOONSET, ON THE SHADED SIDE OF THE MOUNTAIN, IN A NEAR WINGS LEVEL ATTITUDE. NO PREIMPACT/MECHANICAL MALFUNCTION/FAILURE WAS FOUND, BOTH ENGS/PROPS SHOWED EVIDENCE OF POWER. THE PLT'S WIFE SAID HE SOMETIMES FLEW OVER THEIR HOUSE TO LET HER KNOW HE WOULD BE HOME SOON. COMPLETE AUTOPSY/TOX CHECK NOT PSBL.