On September 17, 1995, at 1150 hours Pacific daylight time, a Piper PA-28R-200, N41544, collided with the ground following a loss of control during a landing attempt at a dirt airstrip near Parker Dam, California. The aircraft was owned and operated by the pilot and was on a personal cross-country flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft incurred substantial damage. The certificated private pilot and his one passenger sustained serious injuries. The flight originated from Las Vegas, Nevada, on the day of the accident at 1000 as a flight to the dirt airstrip. According to information developed during the investigation, the flight departed John Wayne Airport, Santa Ana, California, about 1100 on the morning of September 16 and flew to Las Vegas. The fuel tanks were filled to capacity with 100LL aviation gasoline while at Las Vegas. The flight then left Las Vegas on the morning of the accident for the flight to the Havasu Palms airstrip, where the pilot was to meet a relative. The pilot stated that he had no recall of the accident sequence. Ground witnesses saw and heard the aircraft make an approach to the runway from the river towards the south. The weather was described by one witness as clear with light winds of 2 knots from the west. Another witness stated that the winds were 25 knots from the east. The aircraft was observed to approach with the landing gear down, then "the engine reved up and the pilot pulled up and turned left." One witness said the aircraft stalled, then descended to ground impact across the ravine. A pilot-rated witness said the engine sounded normal throughout the sequence. The dirt airstrip is on the west bank of the Colorado River and sits atop a small plateau bordered by ravines on the east, west, and north sides. Oriented in a north-to-south direction, the runway is about 2,200 feet long by 60 feet wide. The north end of the runway is the closest to the river. The south end of the runway has rapidly rising terrain within 1/2-mile. Review of both FAA and California Department of Aeronautics airport files revealed no listing for the airstrip. It is not depicted on any aeronautical chart. Personnel from the aircraft retrieval firm which recovered the wreckage were interviewed. A diagram of the airstrip, surrounding terrain, and the location of the aircraft was produced based on this interview and is attached to this report. The aircraft was found about 1,200 feet down the runway and 150 yards to the east of the runway center line and across a ravine. The aircraft was resting against the trunk of a 25-foot tall tree on the opposite upslope side of the ravine. The tree contacted the aircraft at the right wing root-to-fuselage junction and had severely damaged the wing root area and adjacent fuselage. Photographs of the aircraft taken during wreckage recovery were examined. Extensive crush deformation was noted to the lower engine cowl and forward fuselage areas near the firewall. The axis of the crush deformation was about 40 degrees to the horizontal. Full span leading edge crush and upward deformation was observed on the left wing forward of the main spar. After recovery from the accident site, the aircraft was examined by Safety Board investigators with technical assistance from Piper Aircraft and Textron Lycoming. The main landing gear was found extended, with the trunions broken in a direction consistent with a loading in an aft direction. No vertical loadings were evident. The nose landing gear was found folded aft into its respective gear well. No deformation was observed to the nose landing gear strut. Control system continuity was established from the control surfaces to the locations where the cables were cut by the recovery crews, and from the cut points to the cockpit controls. The position of the flaps could not be determined. The stabilator trim jackscrew was found with 13 threads exposed; according to Piper, this corresponds to a near full nose-up trim setting. Fuel system continuity was established from the tanks to the engine, and included the fuel tank vent lines. Fuel was found in the gascolator, electric pump, engine driven pump, distributor, and fuel servo. The propeller hub remained attached to the engine crankshaft. Both blades were free to rotate within the hub and were found in a near feathered position. Both blades exhibited extensive leading edge damage, cordwise scoring, and tip end curls. The engine crankshaft was rotated by hand, with valve train and accessory gear continuity established. All cylinders produced compression. All spark plugs were clean and dry, with normal ovaling signatures observed on the electrodes. The induction and exhaust systems were clear. Engine control continuity was established from the cockpit to the fuel servo and throttle butterfly. Magneto-to-engine timing was found to be 19 degrees for the left and 20 degrees for the right. The impulse coupling was intact and functional on the left magneto. Hand rotation of both magnetos produced strong sparks in normal firing order at the spark plug ends of the ignition leads. The engine was then completely disassembled for detailed internal examination. The starter housing exhibited impact damage. Flywheel rubbing was found on the starter housing. No internal discrepancies were noted.