THE ACFT CRASHED SHORTLY AFTER TAKEOFF IN IFR WEATHER. THE PLT FAILED TO FOLLOW ESTABLISHED DEPARTURE PROCEDURES AND IN FACT HE DID NOT EVEN CALL IN THE FACT THAT HE HAD DEPARTED OR HIS DEPARTURE TIME AS INSTRUCTED BY SALT LAKE CENTER. ATTEMPTS BY SALT LAKE CENTER AND IDA FSS TO CONTACT THE ACFT WERE UNSUCCESSFUL. FROM TIME OF TAKEOFF UNTIL THE CRASH THERE WAS NO COMMUNICATION FROM THE ACFT. THE ACFT DEPARTED ABOUT 0840 MST AND CRASHED ABOUT 05-15 MINUTES LATER. THE ACFT WAS FOUND 3 MILES NORTH AND 1 MILE WEST OF THE DEPARTURE ARPT ABOUT 5 DAYS AFTER THE ACCIDENT. THE MINIMUM SAFE ALTITUDE FOR TERRAIN CLEARANCE IN THE AREA OF THE ACCIDENT ON THE ACFT HEADING OF 260 DEGREES IS ABOUT 12000 FT MSL. THEACCIDENT SITE ELEVATION WAS 7740 FT. THE WEATHER WAS CEILING 1000 FT SKY OBSCURED VISIBILITY 2 MILES LIGHT SNOW WIND CALM. THE ACFT IMPACTED IN A LEFT WING LOW NOSE LOW ATTITUDE INTO TALL PINE TREES AND SNOW COVERED GROUND.