DRG VFR FLT AT NGT, PLT TRIED CTCG ALBANY APCH CTL (ALB), 40 MI FM DESTN. CTLR ANSWERED CALL & RPRTD HE WAS NOT RCVG TRANSPONDER (XPDR), BUT PLT DID NOT HEAR HIM AS HIS ACFT WAS TOO FAR AWAY. PLT WAS ADZD, VIA AN AIRLINER, TO CALL AGAIN AFTER PROCEEDING FURTHER INBND. ABT 13 MIN LATER, PLT ESTABLISHED CTC WITH ALB, APRX 27 MI SE IN VCNTY OF PITTSFIELD AT 2500' MSL. HE ASKED, 'MY ALT OF 2500, IS THAT OK?' CTLR THOUGHT PLT WAS REFERRING TO QUALITY OF XPDR READ-OUT OF 2500' & REPLIED 'AFFIRMATIVE.' CTLR THEN ASKED IF PLT WAS VFR; PLT SAID HE WAS. SOON THEREAFTER, CTC WITH ACFT WAS LOST. IT DSCNDED INTO RISING TRRN AT ELEV OF ABT 1800'. NO PREIMPACT MECH PRBLM WAS FND. DRG PREFLT WX BRIEFING, FSS PSNL DID NOTADZ PLT OF FLT PRCTN OF OBSCD MTNS. MVA IN AREA WAS 4000' MSL. ANOTHER PLT OPERG FM PITTSFIELD RPRTD BASES OF OVC WERE RAGGED AT 2500' TO 3000' MSL & HIGHER TRRN WAS OBSCD BY CLOUDS. RCC NOT NOTIFIED; SEARCH DELAYED; CTLR'S SUPVR NOTIFIED ARTCC PER PROC FOR IFR ACFT. ARTCC DID NOT NOTIFY RCC, SINCE ACFT WAS VFR; HOWEVER, CRASH WAS NOT SURVIVABLE.