At approximately 07:30 Pacific time, a Cessna U206F on a Part 135 flight nosed over during the landing roll at a private airstrip about 13 nm northeast of Imnaha. The pilot said he circled the airstrip, located in a canyon, three or four times to determine the wind direction. He then set up for an approach to the southeast. He said the wind sock was limp during the approach, but shortly after touchdown a gust of wind picked the aircraft up and dropped it. The pilot opted to continue the landing instead of going around, but didnt have enough room to stop. He tried to ground loop the aircraft, but the nose gear separated and the airplane flipped inverted.