On November 2, 2000, approximately 1900 Pacific standard time, a Cessna 172N, N734UW, nosed over during the landing roll in a plowed field adjacent to the turf runway at Spangle Field, Spangle, Washington. The private pilot, who was the sole occupant, was not injured, but the aircraft, which was owned and operated by Felts Field Aviation, sustained substantial damage. The 14 CFR Part 91 personal pleasure flight, which departed Felts Field, Spokane, Washington, about 25 minutes earlier, was being operated in night visual meteorological conditions. No flight plan had been filed. The ELT did not activate. According to the pilot, who was attempting to land at the unlighted field on a dark night, after turning on his landing light and making two low passes over the field, he decided to land. Because there were trees off the approach end of the runway, he came in high with full flaps and then cut the power to idle over the end of the runway. Seeing that he was too high and realizing that he needed to initiate remedial action, he slipped the aircraft to the left in order to lose altitude. During the slip sequence, the aircraft drifted beyond the side boundary of the runway and touched down in an adjacent plowed field. Although the touchdown was uneventful, during the landing roll, the nose gear dug into the soft terrain and the aircraft nosed over. According to the pilot, he did not realize he had drifted beyond the runway edge until the aircraft encountered the soft terrain.