NMAC AT NON TWR ARPT WITH OPPOSITE DIRECTION LNDG TFC.

Narrative

BEAUTIFUL CALM VFR DAY. UNCTLED ARPT WITH UNICOM ON 122.8. ALL ACFT USING RWY 17. I ARRIVED FROM HPN; ENTERED L DOWNWIND TO RWY 17 AFTER ANNOUNCING ON UNICOM FREQ. I TURNED L BASE ABOUT 1 MI N AND ANNOUNCED IT. I TURNED ABOUT 1 MI FINAL AND ANNOUNCED IT. MY LNDG LIGHT WAS ON ALL THROUGHOUT. SEVERAL PRIOR ACFT USED RWY 17 FOR TKOFS AND LNDGS. WHEN I WAS ON SHORT FINAL -- MAYBE ONE HALF MI -- A HIGH WING ACFT TOOK OFF ON RWY 17 TOWING A GLIDER. SPACING WAS ADEQUATE. I ANNOUNCED SHORT FINAL; THEN TOUCHED DOWN IN THE FIRST ONE THIRD OF THE RWY AND PROCEEDED TO ROLLOUT. WHEN I WAS ABOUT HALF WAY DOWN RWY 17 AND DECELERATING; I SAW A PIPER CHEROKEE (WHITE WITH RED TRIM) ABOUT 20 FT ABOVE ME AND SLIGHTLY AHEAD; GOING IN THE OPPOSITE DIRECTION -- AS IF ABOUT TO LAND ON RWY 35. I QUICKLY SWERVED OFF THE RWY TO MY R AND THIS CHEROKEE LANDED BEHIND ME ON RWY 35. I CALLED TWICE ON UNICOM TO ASK THE PLT WHY HE DID THAT; AND ON MY SECOND CALL I GOT A GARBLED UNINTELLIGIBLE RESPONSE THAT 'SOMETIMES IT IS CONFUSING AND YOU HAVE TO BE CAREFUL' OR SOME SUCH REMARK. THIS PIPER; I LATER LEARNED; IS BASED AT N31 AND AS STATED; IS WHITE WITH RED TRIM; FIXED GEAR; I BELIEVE. NO ANNOUNCEMENT EVER CAME FROM THAT CHEROKEE.