On August 31, 1994, at 1210 Alaska daylight time, a wheel equipped Cessna 170B airplane, N4457B, registered to and operated by the Pilot, a registered hunting guide, experienced a collapsed main landing gear during landing on an airstrip on the Upper Coleen River, located 100 nautical miles west of Arctic Village, Alaska. The business flight, operating under 14 CFR Part 91, departed a field site in connection with a guided hunting trip. The destination was the accident site. No flight plan was filed and visual meteorological conditions prevailed. The pilot, the sole occupant, was not injured and the airplane was substantially damaged. According to the pilot, the left main gear leg broke through the wheel axle upper mounting hole. Although the airplane was on wheels at the time of the accident, the airplane has been used on skis extensively during the winter months. Visual examination of the landing gear leg showed a small area of striations. The striations point to a spot near the center of the upper axle mounting bolt, on the inside of the gear leg. According to the pilot, the landing gear leg had more than 1500 hours of total time.