Abstract: ROAD CREW EMPLOYEES OF YOSEMITE NATIONAL PARK WERE CLEARING ROCKS AND SNOW FROM HIGHWAY 120 (TIOGA PASS ROAD). THIS OPERATION INVOLVED THE BLASTING OF VARIOUS ROCKS FROM CUTS TO PREVENT THEM FROM SLIDING ONTO THE ROADWAY. A THREE MAN CREW, CONSISTING OF A BLASTER (IN CHARGE) AND TWO EMPLOYEES ACTING AS FLAGMEN, WERE ASSIGNED TO THE WORK. DURING THE BLASTING OF A BOULDER, ONE OF THE FLAGMEN WAS STRUCK IN THE HEAD BY A FLYING ROCK. HE WAS APPROXIMATELY 453 FEET, STRAIGHT LINE DISTANCE, FROM THE SITE OF THE BLAST, WHICH WAS LOCATED AROUND A CURVE IN THE ROADWAY. THE BLASTER WAS 341 FEET AWAY, AND THE OTHER FLAGMAN WAS 391 FEET AWAY IN THE OTHER DIRECTION. HE WAS ALSO AROUND A CURVE IN THE ROAD. EMPLOYEE #1 WAS THE INJURED EMPLOYEE. THE BLAST CONSISTED OF TWO CHARGES OF 10 STICKS EACH OF 60% DYNAMITE, FIRED BY ELECTRIC BLASTING CAPS. ALL BLASTING PROCEDURES AS OUTLINED IN THE YOSEMITE PARK BLASTING MANUAL, WITH THE EXCEPTION OF THE DISTANCES FROM THE BLAST SITE, WERE BEING FOLLOWED DURING THIS OPERATION. THE DISTANCES TO BE MAINTAINED FROM THE BLAST SITE ARE LEFT UP TO THE BLASTER IN CHARGE. HE DETERMINED THAT THE DISTANCES WERE SUFFICIENT TO PREVENT INJURY.