On March 28, 1998, at 1225 mountain standard time, a Cessna 180, N9140C, operated by commercial instrument pilot collided with electrical wires followed by the terrain while attempting an off airport landing in Whitewood, South Dakota. The pilot was not injured and the airplane was substantially damaged. The 14 CFR Part 91 flight was operating in instrument meteorological conditions without a flight plan. The flight originated from Spear Fish, South Dakota, at 1155 mst, with an intended destination of Walker, Minnesota. The pilot reported to an inspector from the Rapid City, South Dakota, Federal Aviation Administration Flight Standards District Office (FSDO) that he was flying between cloud layers at 7,500 feet above mean sea level when the airplane started to pick up ice. He reversed his direction to return to Spear Fish, South Dakota, but the weather continued to deteriorate at which time he decided to make an off airport landing in a field. The pilot reported that he circled the field two times. On the third pass, while on final approach, the airplane contacted the lower line of a dual set of wires. According to the FSDO inspector, the airplane nosed down and impacted the terrain prior to nosing over inverted.