LEFT FRONT FIRESTONE TIRE BLOW-OUT- DRIVING MY 1999 FORD F250 AND PULLING A 21 FOOT FAMILY RUNABOUT STYLE BOAT NORTH OF FRESNO ON HIGHWAY 41 TO BASS LAKE. AS I ENTERED THE HIGHWAY AT FRESNO, I FELT A SLIGHT VIBRATION IN THE TRUCK WHICH FELT LIKE A SLIGHTLY "OUT OF BALANCE" TIRE. I HAD NOT HAD A BOUNCE BEFORE AND THOUGHT I NEEDED TO HAVE THE TIRES BALANCED ON RETURN FROM BASS LAKE. 10 MILES NORTH, THE LEFT FRONT TIRE EXPLODED / TREAD SEPARATION -(FIRESTONE STEELTEX A/T - LT 265/75R16, LOAD RANGE E). LOSS OF CONTROL OF TRUCK AND TRUCK AND TRAILER CAUSING SWERVING INTO ONCOMING LEFT LANE OF TRAFFIC. REGAINED CONTROL BEFORE HITTING ONCOMING TRAFFIC. DAMAGE TO LEFT FENDER, INNER FENDER, FRONT BUMPER, RUNNING BOARD AND BRAKE HOSE - REPAIR ESTIMATE $2000. 7/32" TREAD REMAINED- TIRE PRESSURE IS CHECKED MONTHLY AND WAS CHECKED AGAIN THAT MORNING JUST BEFORE LEAVING FOR DRIVE TO BASS LAKE. *TR