On October 22, 2005, approximately 1300 Pacific daylight time, a Michael Moneyhan Magnum, single-engine airplane, N686JM, sustained substantial damage after impacting terrain and nosing over near Cougar, Washington. The airplane was registered to and operated by a private individual. The certificated private pilot and his sole passenger sustained minor injuries. Visual meteorological conditions prevailed at the time of the accident, which was operated in accordance with 14 CFR Part 91, and a flight plan was not filed. At 1200 the local flight departed the Walter Sutton Private Airstrip (WA79), Amboy, Washington. In a written statement the pilot reported that after making two low approaches over the sand bar looking for a good place to land, "...I thought I had picked out a nice flat and hard place; there were All Terrain Vehicle (ATV) tracks on it and they appeared not to be very deep and the area looked flat." The pilot further reported that after he had touched down and was rolling out, "...deep swales appeared in front of me that could not be seen from the air. I applied full power to go around, but was unable to get flying speed before I could avoid hitting the first one." The pilot stated that the airplane bounced and hit terrain with its right wing tip and flaperon, before closing the throttle. The pilot reported that as he was pulling the mixture to full lean the airplane hit a third swale, resulting in both main landing gear separating from the airplane before nosing over and coming to rest in an inverted position. The pilot stated that the swales were not visible to him due to the "bright, sunny day." The pilot reported that damage to the airplane included the left wing and both wing struts being bent, the propeller and propeller spinner destroyed, the rudder bent, and the right wing damaged.