On April 15, 2000, about 1430 Alaska daylight time, a wheel equipped Piper J3C-65 airplane, N88472, sustained substantial damage while landing at an off airport site, about 12 miles northwest of Anchorage, Alaska, at 61 degrees, 12 minutes north latitude, 149 degrees, 50 minutes west longitude. The certificated private pilot, and the one passenger aboard, were not injured. The airplane was being operated as a visual flight rules (VFR) personal flight under Title 14, CFR Part 91, when the accident occurred. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated about 1400, from the Lake Hood Airstrip, Anchorage, Alaska. During a telephone conversation with the National Transportation Safety Board investigator-in-charge on April 17, the pilot reported that during the landing roll on a frozen mud flat, the main landing gear wheels broke through a large frozen puddle, and the airplane nosed over. The airplane sustained substantial damage to the left wing lift struts, vertical stabilizer, and rudder. The pilot reported there were no preaccident mechanical problems with the airplane.