DOZER BACKING UP IN RUN RIGHT TRACK WENT UP ON A ROCK DOZER TURNED OVER ON LEFT SIDE. SEAT BELT CAUGHT OPERATOR AROUND MIDDLE. TOOK HIM TO EMERGENCY ROOM TO BE CHECKED. THEY RELEASED HIM FROM EMERGENCY ROOM AROUND 4:00 AM ON 3/12/2003. EMERGENCY ROOM DR GAVE HIM A SLIP TO RETURN TO WORK ON 3/13/2003.