On February 4, 2001, at 1605 hours Pacific standard time, an amateur built Fish RV6, N1198N, was substantially damaged during an off-airport emergency landing following loss of engine power near Georgetown, California. The private pilot and the sole passenger were not injured. The personal flight departed from Silver Springs, Nevada, at 1500, and was destined for Castle Airport at Atwater, California. The flight was operated by the owner under 14 CFR Part 91, and no flight plan was filed. Visual meteorological conditions prevailed. The pilot reported that the engine lost power while in cruise flight, and, although there was oil pressure, eventually seized before the landing. During the landing in a forest clear cut area, the landing gear impacted a tree trunk and the aircraft nosed over. Post accident disassembly of the engine revealed that the crankshaft separated at the crankshaft cheek between the number 3 and 4 throws. The owner reported he assembled the (experimental) engine himself using Lycoming parts, and that the engine had accumulated 631 flight hours since assembly. The owner was not a certificated powerplant mechanic.