THE ACFT CRASHED INTO THE SIDE OF A MOUNTAIN RIDGE DURING A VFR ATTEMPT TO LAND AT AN ARPT WITH NO INSTRUMENT APPROACH. THE MOUNTAIN RIDGE WAS OBSCURED BY BROKEN CLOUNDS. THE PLT HAD CANCELLED HIS IFR CLEARANCE, & DURING THE DESCENT TO THE ARPT, HE HAD DESCENDED BELOW CLOUDS NEAR THE ARPT WITH CLOUDS STILL OBSCURING SOME OF THE TERRAIN. ONE MILE VISIBILITY WAS A REQUIREMENT FOR THE VFR APPROACH. ACCORDING TO WITNESS STATEMENTS, THE ACFT CONTINUED TO REMAIN BELOW THE CLOUDS & THE PLT CONTINUED THE APPROACH EVEN THOUGH HE WAS NOT PROPERLY POSITIONED TO MAKE A SUCCESSFUL LANDING. THE PLT HAD A PARTIAL OCCLUSION OF A CORONARY ARTERY, BUT ITS RELATIONSHIP TO THE ACCIDENT WAS NOT DETERMINED. THE ACFT IMPACTED AT ABOUT 6250 FT MSL. THE FIELD ELEVATION IS 5315 FT MSL. THE ACCIDENT SITE WAS ABOUT 2 1/2 MI FROM THE ARPT. THE ARPT WAS LOCATED IN A MOUNTAIN VALLEY ABOUT 1 TO 1.25 MI WIDE. ALSO, THE ARPT & SURROUNDING TERRAIN WERE COVERED WITH SNOW.