On August 23, 2004, at approximately 1505 mountain daylight time, a Bell 206B3, N2751U, operated by Hawkins and Powers Aviation, Inc., was substantially damaged when it struck high, rolling terrain while maneuvering near Atlantic City, Wyoming. Visual meteorological conditions prevailed at the time of the accident. The local flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The commercial pilot and one passenger received serious injuries and two passengers received minor injuries. The flight originated at approximately 1415. According to the pilot, he was engaged in a filming operation. He was completing a "high groundspeed" pass and was slowing to approximately "20 mph" into the wind. At approximately 75 feet above the ground, and an airspeed of approximately 60 knots, the pilot continued to maneuver the helicopter around the leeward side of a small hill. During the maneuver, the helicopter encountered a sudden wind shear and a "15 to 20 knot tailwind." The pilot stated that helicopter lost all response to control inputs, and he was unable to maintain altitude. The helicopter descended, struck the terrain and rolled over. The impact crushed the forward fuselage, separated the main rotor assembly, and buckled the tail boom. At 1453, the recorded wind condition at Hunt Field (LND), Lander, WY, located approximately 23 nautical miles at 350 degrees, elevation 5586, was, 210 degrees at 15 knots, gusting to 18 knots.