PRIOR TO DEPARTING HELENA, MT AT 1209, THE PLT RECEIVED A WX BRIEFING FROM THE GREAT FALLS FSS. THE DFW 021240Z AREA FORECAST, VALID UNTIL 0700Z ON 11/3/82, WAS NOT AVAILABLE. THE FSS BRIEFER MADE THIS DEFICIENCY KNOWN TO THE PLT & RECOMMENDED THAT HE RECEIVE ANOTHER BRIEFING DURING HIS REFUELING STOP IN THE SALT LAKE CITY AREA. THE FORECAST CALLED FOR CLOUDS 7000-10000 FT WITH SCATTERED SHOWERS & SNOW SHOWERS OVER NW NMEX SPREADING EASTWARD OVER THE STATE DURING THEAFTERNOON. MOUNTAIN TOPS WOULD BE LOCALLY OBSCURED ABOVE 6000 FT. AIRMET XRAY 1 WAS IN EFFECT FOR THE AREA IN QUESTION CALLING FOR TERRAIN OBSCURATION IN CLOUDS ABOVE 6000 FT & PRECIPITATION WITH FREQUENT RIME ICING BETWEEN 8000 FT & 1400 FT MSL. THE FLT ARRIVED IN OGDEN, UT ABOUT 1400 & SUBSEQUENTLY DEPARTED 1500-1530. THERE IS NO RECORD THAT THE PLT REQUESTED ANOTHER WX BRIEFING. THE ACFT IMPACTED TREES ON THE NE SLOPE OF CANJILON PEAK AT THE 10,481 FT LEVEL. THE WX INFO ON THE PREVIOUS PAGE WAS THE 1852 OBSERVATION AT FARMINGTON, NM LOCATED 100 MI WEST OF THE ACCIDENT SITE.