According to the pilot, he was herding cattle with the helicopter. He descended to an altitude of about 10 feet to get the cattle to turn and enter a pen. After the cattle entered the pen, he maneuvered away and gained altitude to clear some nearby trees. The pilot thought the helicopter was clear of the trees; however, the tailrotor impacted a tree. The helicopter started to spin, so he reduced the throttle to stop the spin. The helicopter impacted terrain, resulting in substantial damage the main rotor blades , fuselage, and tailboom.