DRG ARR FOR A LOC RWY 26 APCH, THE PLT WAS ADZD THE ABYSS FAN MARKER WAS NOTAMED OUT-OF-SVC. WITH ABYSS INOP, MIN DSCNT ALT (MDA) WAS 2200'. AFTER N65TD WAS CLRD FOR THE APCH, RADAR SVC WAS TERMINATED & THE FLT WAS CLRD TO ADZY FREQ. THE CREW CONTACTED UNICOM & OBTAINED ARPT & WX ADZY. UNICOM OPERATOR ADZD WINDS LGT & VRBL, ESTD 800' OVERCAST, VIS 5 MI, SLUSH & ICE RPRTD ON RWY 1/2 HR EARLIER. AFTER THE CREW RPRTD 'PROCEDURE TURN INBND,' NO FURTHER TRANSMISSIONS WERE RECDFM THE ACFT. SUBSEQUENTLY, IT HIT TREES ON RISING TRRN AT AN ELEV OF APRX 2200', APRX 7 MI BFR REACHING THE FINAL APCH FIX (FAF, DALTON NDB). MIN ALT FOR THE APCH IN THAT AREA WAS 3000'. NO PREIMPACT PART PRBLMS WERE FND DRG THE INV. WIT- NESSES RPRTD THE ENGS SOUNDED NORMAL BFR IMPACT; MTN TOPS WERE OBSCD. ARPT ELEV WAS 1194'. RADIO TRANSCRIPTS INDCD THE CREW WERE GETTING A WEAK SIGNAL FM THE DALTON NDB. ALTHO NOT A REQD NAVAID, CHESTER VORTAC WAS DEPICTED ON THE APCH CHART AS AN ADNL SOURCE TO ID THE FAF, BUT WAS NOTAMED AS OUT-OF-SVC. THE PLT DID NOT OBTAIN NOTAMS BFR FLT.