EMPLOYEE WAS DRIVING TO BLAST PATTERN IN HIS VEHICLE AT THE BULK STORAGE SITE. THE VEHICLE OVERTURNED ON THE DRIVER SIDE OF THE ROADWAY APPROX 1050 FT FROM THE BULK STORAGE AREA. EMPLOYEE HAD NO RECOLLECTION OF HOW THIS HAPPENED AND THERE WERE NO WITTNESSES. EMPLOYEE WAS IN COMPLIANCE WITH RULES AND REGULATIONS. ACCIDENT DID NOT INVOLVE MINING EQUIPMENT.