EE WAS PARKED, WAITING TO BACK UP AND GET LOADED. HIS HAUL TRUCK WAS FACING THE HIGHWALL APPROX. 30 FT. FROM IT. A LARGE ROCK APPROX. 5 SQUARE FT. ROLLED DOWN THE HIGHWALL 180 FT. AND STRUCK T HE FRONT GRILL OF THE HAUL TRUCK. THE FORCE LIFTED THE REAR WHEELS 3 FT. OFF THE GROUND CAUSING THE EE TO STRIKE HIS FACE AGAINST THE STEERING WHEEL.