THE PLT, HIS BROTHER & HIS SISTER-IN-LAW WERE ON A FLT TO ATTEND HIS MOTHER'S FUNERAL. BEFORE TAKING OFF, THE PILOT RECEIVED A WX BRIEFING & WAS ADVISED THAT VFR FLT WAS NOT RECOMMENDED. THE PLT THEN ASKED FOR WX REPORTS FOR A SOUTHERLY ROUTE & HE WAS ADVISED THAT THE MOUNTAIN TOPS WERE OBSCURED ON THAT ROUTE. HE THEN INDICATED THAT HE WOULD TRY & THAT MAYBE THE WEATHER WOULD CLEAR ENOUGH FOR HIM TO GET THRU. SUBSEQUENTLY, THE ACFT CRASHED ON THE SIDE OF MT DEMOCRAT, A 14,286 FT MOUNTAIN, AT THE 13,800 FT LEVEL. THERE WAS EVIDENCE THAT THE ACFT IMPACTED IN NEAR LEVEL FLT. NO PREIMPACT PART FAILURE OR MALFUNCTION WAS FOUND THAT WOULD HAVE CONTRIBUTED TO THE ACCIDENT. THE AREA FORECAST CALLED FOR MOUNTAINS & HIGHER TERRAIN TO BE OCCASIONALLY OBSCURED IN CLOUDS & PRECIP; ROCKY MOUNTAINS 3000 TO 6000 FT THRU 20,000 FT WITH OCCASIONAL CEILINGS BELOW 1000 FT & VISIBILITY BELOW 3 MILES IN SNOW & FOG.