On July 31, 2001, at 1347 mountain daylight time, a Bell 205A-1 helicopter, N205BR, sustained substantial damage to both main rotor blades when the water bucket of a Bell 212 helicopter, N911VR, contacted its main rotor system near Jackson, Wyoming. The Bell 205A-1 helicopter was registered to Idaho Helicopters, Inc., of Boise, Idaho, and the Bell 212 helicopter was registered to Rogers Helicopters, Inc., of Fresno, California. Both helicopters were being operated by the U.S. Forest Service as public use fire fighting flights. The airline transport pilot of the Bell 205A-1 and the airline transport pilot of the Bell 212 were not injured. Visual meteorological conditions prevailed for the local flights. A company flight plan was filed for the Bell 205A-1 and a flight plan was not filed for the Bell 212. Both flights originated from Wilson, Wyoming. Witnesses reported observing the Bell 205A-1 helicopter at an out-of-ground effect hover over a pond near the Snake River using a long line and bambi bucket to pick up water during fire fighting operations. While the Bell 205A-1 helicopter was filling its bucket, the Bell 212 helicopter came to a hover above it. As the Bell 205A-1 helicopter prepared to depart the pond, the bambi bucket of the Bell 212 helicopter contacted its main rotor system. The pilot of the Bell 205A-1 performed an autorotation, and the helicopter came to rest with the tail section and part of the fuselage in the pond. The Bell 212 departed the area. The pilot of the Bell 205A-1 helicopter reported that while picking up water with a bucket on a 100-foot long line, "[the main rotor] was hit by something." Subsequently, he performed an autorotation with power to the shoreline. The pilot of the Bell 212 helicopter reported that he was flying north along the Snake River, with a 100-foot long line and bambi bucket, and was slowing and turning west to enter one of several dipping ponds. He saw the Bell 205A-1 helicopter "approaching downhill from the west and assumed he would take one of the western ponds while [he] turned into the wind (SW) for [his] dip into the NE most pond." The pilot stated that "as I was slowing and lowering the bucket, I saw [the Bell 205A-1] appear under me and I immediately pulled up and turned right." He landed the helicopter at the Green Knoll helibase without further incident.