On March 26, 2006, about 1200 central standard time, a Cessna 180G, piloted by a private pilot, was substantially damaged while landing on runway 9 (4,215 feet by 100 feet, asphalt) at the Eveleth-Virginia Municipal Airport (EVM), Eveleth, Minnesota. Visual meteorological conditions prevailed at the time of the accident. The personal flight was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 91 without a flight plan. The pilot and his three passengers reported no injuries. The local area flight departed EVM about 1130. The pilot reported that the airplane's main landing gear were equipped with wheel skis. During final approach, the airplane's airspeed was 55-60 mph and there was a left quartering headwind of 10 knots. The wind decreased just prior to touchdown and a light bounce was encountered during initial touchdown. After the second touchdown, forward stick pressure was used to keep the airplane on the runway with the tail up. During the landing rollout the left wing began to drop and the right wing began to rise-up. The pilot used right aileron and rudder in an attempt to level the wings and maintain directional control, but the airplane continued to swerve toward the left side of the runway. He increased engine power to provide additional airflow over the control surfaces, but the airplane continued the left swerve. The pilot decided to reduce engine power and allow the airplane to depart the runway onto a snow covered area. The pilot reported that he had to subsequently increase engine power to prevent the airplane from impacting a series of drainage ditches. However, the airplane impacted one of the drainage ditches and an airport fence before coming to rest. The left landing gear and wheel ski were damaged during the impact with the ditch and fence. The airplane was inspected after the accident and flight control cable continuity was confirmed. No mechanical pre-impact anomalies were noted with the airplane's flight controls or braking system. The left main landing gear structural support was removed for additional examination. The landing gear attachment bolt was bent and fractured, with some evidence of necking. The bolt's fracture occurred along a slant plane and its surface had a matte-gray textured appearance consistent with an overstress separation. The outboard attachment bracket was fractured and bent upward. The bracket's fracture surfaces were all on slant planes and had matte-gray textured appearances consistent with overstress separations. There was no indication of any pre-existing damage or fatigue cracking on any of the examined parts.