C208 PLT IS ACCUSED OF LNDG AT AN ARPT THAT WAS NOTAMED CLOSED.

Narrative

AFTER A 5 1/2 HR FLT; I APCHED CASA GRANDE (CGZ) FROM THE E AND RECEIVED ATIS. I CALLED MY POS AND INTENTIONS AT 6 MI AND 3 MI AND 1 MI OUT ON UNICOM FREQ 122.7. I CROSSED AT MIDFIELD AND NOTICED PERSONNEL AT THE FAR E END OF RWY 23. I CHKED FOR X'S ON THE RWY AND SAW NONE. THERE WERE NO XMISSIONS ON THE UNICOM OTHER THAN ACFT ON PRACTICE APCHS. I MADE A NORMAL APCH OFFSET TO THE R ON FINAL UNTIL PAST THE PERSONNEL AND LANDED WELL DOWNFIELD ON THE LAST 1/2 OF THE RWY; WITHOUT INCIDENT AT XA25. I WAS NOTIFIED LATER THAT THE ARPT WAS CLOSED BY NOTAM FROM XA00-XC00. I GOT MY WX INFO FROM AN INTERNET/TV WX PROGRAM THAT MORNING AND DID NOT CALL FSS. THE ARPT SUPVR SAID THEY CALLED ON THE UNICOM THAT THE ARPT WAS CLOSED; BUT NEITHER MYSELF NOR MY OBSERVER HEARD ANY SUCH XMISSION; NOR DID THE PERSONNEL AT THE FBO. THE FBO PERSONNEL ALSO RPTED THAT NEITHER THEY NOR ANYONE ELSE ON THE ARPT TO THEIR KNOWLEDGE HAD BEEN NOTIFIED OF THE CLOSURE; AND THEY HAD JUST SEEN AN ACFT DEPART BEFORE MY ARR. NO X'S HAD BEEN PUT OUT ON THE RWYS AND NO INFO CONCERNING THE ARPT CLOSURE WAS BROADCAST ON ATIS OR UNICOM.