AT APRX 1720 MDT, TOWER PSNL AT THE DEP ARPT RECEIVED A PHONE CALL FROM THE PLT. HE SAID HE WISHED TO DEPART WITH AN INOP 2-WAY RADIO. HE WAS ADVISED THAT IMC PREVAILED & THAT A RADIO WOULD BE REQUIRED TO DEPART WITH AN IFR OR SPECIAL VFR CLNC. AT 1907 (AFTER OBTAINING A PORTABLE 2-WAY RADIO) THE NON-INSTRUMENT RATED PLT REQUESTED & RECEIVED CLNC FOR A SPECIAL VFR DEPARTURE. HE TOOK OFF WITH A PAX ABOARD, & AT 1917, RPRTD CLEAR OF THE CONTROL ZONE. SUBSEQUENTLY, THE ACFT CRASHED IN MTNS AT AN ELEV OF ABOUT 9500'. INITIAL IMPACT WAS WITH TREES ON RISING TERRAIN AS THE ACFT WAS IN WINGSLVL FLT. THE SURVIVING PAX RPRTD ICE ON THE WINGS & SAID THE ENG WAS RUNNING ROUGH. ALSO, HE SAID THEY WERE FLYING IN SNOW, & WHEN THE PLT PULLED THE CARB HEAT CTL, IT CAME OUT IN HIS HAND; THE CABLE WAS FND BROKEN NR THE BUTTERFLY VLV & ICE & SNOW WERE FND IN THE CARB AIR INTAKE OPENING. CHECKS OF THE PLT'S BLOOD & URINE SHOWED ALCOHOL LVLS OF 0.031% & 0.034%, RESPECTIVELY. COCAINE, METHYL ECGONINE & METHAMPHETAMINE WERE DETECTED IN HIS URINE, BUT NONE FND IN HIS BLOOD.