On June 20, 2000, at 1730 Alaska daylight time, a Cessna 180 airplane, N3229D, sustained substantial damage when it nosed over during landing at the pilot's private airstrip at Miller Creek, 10 miles northeast of Port Alsworth, Alaska, at 60 degrees, 20 minutes north latitude, 154 degrees, 15 minutes west longitude. The solo commercial pilot was not injured. The personal flight was conducted under 14 CFR Part 91, and departed Merrill Field, Anchorage, Alaska, about 1600, for the accident site. Visual meteorological conditions prevailed at the time of the accident, and a VFR flight plan was filed. The pilot told the NTSB investigator-in-charge (IIC), during a telephone interview on June 20, that he was landing to the west on his 1,200 feet long by 100 feet wide airstrip. He indicated that he was aware of a dirt berm on the approach end of his airstrip, and he does not believe the airplane's wheels contacted the berm. He stated that as soon as the airplane touched down, the left landing gear leg dug into the ground, and the airplane nosed over. He described a tire-sized scuff mark leading up to the wreckage on the right side, and a gouge in the dirt leading up to the wreckage on the left side. The left landing gear strut was missing the lower four inches, fracturing at the main landing gear axle attachment bolt holes. The left wheel assembly was located 200 feet from the wreckage. The pilot indicated the airplane had wheel-ski assemblies installed until one month prior to the accident. The lower section of the fractured landing gear leg was inspected at the NTSB materials laboratory on August 16, 2000. The four corners of the fractured bolt holes showed fatigue cracks starting from corrosion pits. Large amounts of corrosion pitting and oxidation were noted on the surface of the gear leg adjacent to the origin of the cracks.