On July 28, 2005, about 1230 Alaska daylight time, a McDonnell Douglas 500D helicopter, Canadian registration C-GBUY, sustained substantial damage during landing when its main rotor blades contacted a small tree at an off-airport landing site, about 49 miles northeast of Delta Junction, Alaska. The helicopter was being operated by the U. S. Department of the Interior, Anchorage, Alaska, as a visual flight rules (VFR) public use flight when the accident occurred. The solo airline transport pilot was not injured. Visual meteorological conditions prevailed, and company flight following procedures were in effect. The flight originated about 1220 at another off-airport site, about 30 miles northeast of Delta Junction. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on July 28, the director of operations for Prism Helicopters, of Pitt Meadows, Canada, noted his company was operating under contract to the U.S. Department of Interior. He related that the pilot of the accident helicopter had reported that the main rotor blades contacted a small tree during landing at an off-airport site, and the extent of the damage to the blades was unknown. He said the pilot reported taking off with two passengers who told him the main rotor blades contacted the tree when he landed to pick them up. In a written statement to the NTSB prepared on July 30, the pilot wrote that he landed in the landing zone, and picked up two workers. During the return flight, he said the workers told him the rotor blades had contacted a small spruce tree when he landed to pick them up. He wrote that he felt a slight feedback in the cyclic control during landing, but didn't think it was anything. Upon landing, he said he examined the blades, and found scratches/dents in the bottom skins of the rotor blades. During a telephone conversation with the NTSB investigator-in-charge on August 27, the director of operations for the operator said the rotor blades were damaged beyond repair.