On August 25, 1996, at 1745 hours Pacific daylight time, a Cessna 172F, N5543R, collided with a runway rock formation while landing on runway 27 at Ocotillo Wells Airport, Ocotillo, California. The pilot was completing a visual flight rules personal flight. The airplane, registered to the pilot and his passenger, sustained substantial damage. Neither the certificated private pilot nor his certificated private pilot/passenger were injured. Visual meteorological conditions prevailed. The flight departed Ramona Airport, Ramona, California, about 1700. The pilot stated in a telephone interview conducted on August 28, 1996, at 1110 hours that the landing was normal. During the landing rollout, however, the setting sun partially blinded him and the airplane drifted and collided with a white painted rock formation at the intersection of runway 27 and 13. He also said that the airplane did not experience any preimpact malfunctions or failures. An Federal Aviation Administration (FAA) inspector from the San Diego, California, Flight Standards District Office reported that the airport is situated on a dry lake bed. He said that the runways are not marked and are dragged annually. The runways are marked with white painted rock formations. According to a computer generated astrological data program, at the time of the accident the sun's elevation was about 18.6 degrees above the horizon. The magnetic bearing toward the sun was 255.4 degrees.