Abstract: A two-person general construction crew working for an electric utility was digging holes for utility poles. The utility was under contract to replace three poles owned by an irrigation district. The worksite was on a steep incline, separated by 3-meter-wide ledges, facing a dam for a reservoir. The employees were transferring their equipment up the hill with ropes and pulleys. While they were doing this, a boulder became dislodged from the side of the hill and rolled down towards one of the employees. His coworker, the crew supervisor, warned him, and he dodged behind a small tree. However, the boulder bounced and careened directly into the employee before he could react. The boulder struck him on the right side of his face and threw him back about 4.5 meters. The injured employee was airlifted to a hospital, where he was treated for a fractured sinus and a concussion.