On June 28, 2002, about 2115 mountain daylight time, an unregistered Infinity two-place powered parachute sustained substantial damage during a precautionary off-airport landing five miles southeast of Lewistown, Montana. The powered parachute is owned by the pilot, and was being operated as a personal/pleasure flight in visual meteorological conditions. The non-certified pilot and passenger sustained serious injuries. The flight originated from the pilot's ranch near Lewistown, Montana. In a written statement, dated September 10, the pilot reported that he was attempting an off-airport landing in an effort to avoid approaching thunderstorms and associated high wind conditions. The pilot reported that on his fourth landing attempt, the aircraft encountered a strong crosswind that "... blew us into the ground." The aircraft sustained substantial damage to the airframe assembly. The pilot estimated the winds at the time of the accident to be 70-80 miles per hour.