CLOSE PROX ACR-SMT UNK-SMT SOUTHWEST OF MSP.

Narrative

WE WERE ENRTE FROM SIOUX FALLS; SD (FSD) TO MINNEAPOLIS; MN (MSP). OUR FILED ROUTE OF FLT HAD BROUGHT US DIRECT TO REDWOOD FALLS; MN (RWF) AND THEN TO JOIN THE BUNKER 6 STAR INTO MSP. WE WERE 2 NM NE OF RWF ON THE ARR WHEN MSP CENTER CALLED TFC AT 10 O'CLOCK AND 2 TO 3 NM AT 13000'; WHICH ALSO WAS OUR ALT; AND THE ACFT WAS S TO SWBND. WE WERE NEBND. IT WAS THE F/O'S LEG TO FLY AND THE VIS WAS SOMEWHAT RESTR BY SMOKE FROM THE YELLOWSTONE FIRES. WE SPOTTED THE TFC WITHIN 2 SEC OF THE CALL AND BY THAT TIME; THE ACFT WAS WITHIN 1 TO 2 MI AND CONVERGING. OUR INITIAL REACTION WAS TO PULL UP TO AVOID COLLIDING; WHICH WE DID; TO AN ALT OF 13500'. THE STANDARD PROC OF A TURN TO THE RIGHT WOULD NOT HAVE BEEN IDEAL IN THIS SITUATION BECAUSE OF HIS APPROX HDG OF 200 DEG AND OURS OF 060 DEG WOULD HAVE PUT US MORE DIRECTLY IN HIS FLT PATH. THE ACFT WAS OBSERVED AS AN SMT WITH BROWN AND GOLD TRIM. I MADE A TELEPHONE CALL TO THE CTLR UPON LNDG AND DISCUSSED THE SITUATION WITH A SUPVR. WE HAD NO PROB WITH ATC; BUT WERE INTERESTED IN MORE FACTS CONCERNING THE SITUATION. WE LEARNED THAT THE ACFT WAS CLBING AT THE TIME THROUGH OUR ALT. BECAUSE OF THE CTLR'S WORKLOAD WITH HIS LARGE AREA; HE HAD NOT SPOTTED THE ACFT UNTIL A VFR INTRUDER ALERT SYS WAS ACTIVATED WITHIN HIS COMPUTER. THE SITUATION DEFINITELY RE-EMPHASIZED THE NEED TO BE CONTINUALLY SCANNING OUTSIDE THE ACFT FOR TFC WHENEVER WX PERMITS; NO MATTER WHAT YOUR ALT IS. SUPPLEMENTAL INFO FROM ACN 93960. THE SMT WAS FLYING DIRECTLY INTO THE SUN IN HAZY SKY FROM RECENT SMOKE BLOWN INTO AREA FROM WESTERN FOREST FIRES.