On August 10, 2002, approximately 0930 Pacific daylight time, a Piper PA-28-235, N32138, sustained substantial damage after colliding with a tree during a forced landing in a field near Creswell, Oregon. The private pilot, the sole occupant of the airplane, sustained serious injuries. The 14 CFR Part 91 personal pleasure flight, originated from Mahlon Sweet Field Airport, Eugene Oregon, approximately 15 minutes prior to the accident, and was being operated in visual meteorological conditions. No flight plan had been filed. In a written statement, dated August 23, 2002, the pilot reported that while in a cruise flight configuration the airplane's engine "…backfired and quit." The pilot reported that he pushed the propeller control and mixture control to the full-forward position, engaged the electric fuel pump and attempted a restart. He reported that the engine successfully started, however, after initiating a climb the engine again lost power and he initiated a forced landing to a nearby field. The pilot reported that while on approach to the field, the airplane collided with a willow tree and the airplane landed short of his intended landing area. A Federal Aviation Administration inspector from the Hillsboro, Oregon, Flight Standards District Office, examined the aircraft after the accident and reported that the fuel selector was found in the "…left tank position." He further reported that the left main tank was empty and that the right main tank was the only tank that appeared to have any fuel quantity. The pilot reported that the purpose of the flight was to reposition the airplane from Eugene to Cottage Grove for refueling.