On December 4, 1998, about 1455 Alaska standard time, a tundra tire equipped Stinson 10A airplane, N36755, sustained substantial damage during a forced landing, about 9 miles east of Nondalton, Alaska. The airplane was being operated as a visual flight rules (VFR) domestic on-demand passenger flight under Title 14 CFR Part 135 when the accident occurred. The airplane was operated by Lake Clark Air Inc., Port Alsworth, Alaska. The certificated commercial pilot, and the sole passenger, were not injured. Visual meteorological conditions prevailed. VFR company flight following procedures were in effect. The flight originated from a private airstrip at Port Alsworth, Alaska, at 1139. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on December 6, 1998, at 1000, the pilot reported the flight was conducted for the Alaska Department of Fish and Game. The passenger was conducting a moose count. The pilot said that after departure with full fuel tanks, he flew for two hours with the left fuel tank selected. After two hours of flight, the fuel in the left tank was almost exhausted, and the pilot switched to the right fuel tank. He then flew for about 1.5 hours on the right tank before the engine suddenly quit. The pilot switched back to the left tank and climbed to about 1,000 feet above the ground. After about 6 minutes on the left tank, the engine quit running again. The pilot selected an emergency landing area on a small, frozen pond. The surface of the pond contained slushy ice and drifted snow. During the landing roll, the airplane entered deep snow and nosed over. The airplane received damage to the left wing lift strut, the rudder, and the right wing tip. The operator reported the airplane is equipped with a 150 horsepower engine. The airplane has two wing mounted fuel tanks that contain 20 gallons each. Total useable fuel is 36 gallons. The fuel selector has positions for left, right, and off. Each fuel tank has an electric fuel gauge. The passenger was contacted by telephone and interviewed by the NTSB IIC. The passenger reported she flew in the accident airplane two days before the accident. During that flight, she noticed the right fuel gauge in the airplane was inoperative. During the accident flight, two days later, she again noticed the right fuel gauge was still inoperative. The operator reported that when the airplane was recovered from the accident site, evidence of fuel staining was observed on the upper surface of the right wing, adjacent to the right fuel cap. A Federal Aviation Administration (FAA) operations inspector with the Anchorage Flight Standards District Office, Anchorage, Alaska, inspected the airplane after it was recovered. He found evidence of fuel staining on the right wing, adjacent to the right wing fuel cap.