MTR HAD AIRBORNE CONFLICT WITH SMA IN ADJACENT ARPT AIRSPACE EVASIVE ACTION TAKEN. SEE AND AVOID CONCEPT.

Narrative

I WAS WORKING LCL POS AT LAWTON TWR AND RECEIVED A VFR INBOUND FROM FT SILL APCH. RWY 35 WAS ACTIVE AND THE VFR ACFT WAS AN SMA INBOUND FROM THE NE FOR A R DOWNWIND. ADDITIONAL TFC IN THE ATA WAS AN MTR ON A PAR APCH TO HENRY POST ARMY AIRFIELD; 4 MI N OF LAWTON. THE PAR FINAL IS ALONG THE E SIDE OF THE RWY AT LAWTON MUNICIPAL (OPPOSITE DIRECTION TO R DOWNWIND AT LAWTON). BOTH ACFT HAD BEEN HANDLED BY FT SILL APCH AND THEY HAD ADVISED ME OF THE PAR TFC. LAWTON TWR DOES NOT HAVE ANY TYPE RADAR AND MUST RELY ON VISUAL CONTACT TO PROVIDE POSITIVE SEPARATION. I WAS LOOKING FOR THE SMA AND HAD TOLD HIM ABOUT THE MTR BUT COULD NOT PROVIDE POSITIVE SEPARATION BECAUSE I DID NOT HAVE EITHER ACFT IN SIGHT INITIALLY. I FINALLY SAW THE SMA AS HE ENTERED R DOWNWIND AND A FEW SECONDS LATER SAW THE MTR. THE ACFT WERE HEAD-ON; LESS THAN A MI AT APPROX THE SAME ALT. THE MTR TOOK EVASIVE ACTION AND THE SMA SAW HIM IN THAT MANEUVER. SINCE FT SILL HAD WORKED BOTH ACFT; GIVEN ME THE VFR INBOUND ON THE SMA AND ADVISED ME OF THE MTR TFC; I BELIEVED THEY HAD RESOLVED ANY POSSIBLE CONFLICT. DISCUSSIONS WITH FT SILL REVEALED THAT THE ACFT WERE BEING WORKED BY SEPARATE CTLRS WHO DID NOT COORD WITHIN THEIR FACILITY. IF LAWTON TWR HAD A BRITE RADAR I WOULD HAVE BEEN ABLE TO POINT OUT THE TFC TO THE SMA AND AVOIDED A SITUATION REQUIRING EVASIVE ACTION.