On September 26, 2002, at 0830 central daylight time, a Robinson R22 Beta helicopter, N888MH, was substantially damaged upon collision with power lines and subsequent impact with terrain near Freer, Texas. The aircraft was registered to and operated by Mesquite Helicopter Service, Inc., of Alice, Texas. The commercial pilot and his passenger were not injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 CFR Part 91 flight. The local flight departed from ranch headquarters near Freer at 0745. According to the Pilot/Operator Accident Report (NTSB form 6120.1/2), and in a telephone conversation with the NTSB investigator-in-charge, the pilot reported that he was using the helicopter to "gather" cattle in a pasture and move them into pens. The pilot stated that he had completed gathering cattle from the first pasture with the owner of the ranch on board, who then instructed him to take one of his farm hands to gather cattle from the second pasture. The pilot reported that he started gathering cattle in the second pasture, flying north and south along the west fence. "The pens were in the southeast corner, so I planned on taking the cows to the east fence and pushing them south to the pens." The pilot reported that the cattle were moving good, but "I noticed one had stayed back near a pond, so I got low to push the cow out of the thicket to get her up to the heard." The pilot stated that he was now flying east, "directly into the sun, in sideward flight" when he struck a 25-foot high power line. The pilot further stated "the helicopter began shaking violently, and there was a lot of grinding noise." The pilot reported that after the helicopter yawed to the right "hard", he rolled off throttle and lowered the collective to autorotate. The helicopter made a three-quarter rotation to the right, hit flat on its skids, and subsequently rolled over on its left side. The pilot and his passenger existed the helicopter uninjured, and there was no post-impact fire. The pilot reported that damage to the helicopter included both main rotor blades being destroyed, and approximately 1 foot of the aft tail boom, including the tail rotor, had separated.