On April 5, 2002, about 1145 Pacific standard time, a Cessna 180J, N7821K, nosed over during landing rollout on an unidentified airstrip in the Saline Valley, Death Valley National Park, California. The airplane was substantially damaged. Neither the private pilot, who owned and operated the airplane, nor the passenger was injured. The airplane was being operated on a personal flight under 14 CFR Part 91. Visual meteorological conditions prevailed, and a visual flight rules flight plan had been filed. The flight originated from Angwin, California, about 0930. According to a spokesperson with the National Park Service (NPS), the airstrip's existence is not depicted on aeronautical charts. Although a windsock is present at the airstrip, no facilities exist and the airstrip is not maintained by the NPS. The spokesperson additionally indicated that the airstrip's runway has a "washboard-like" contour, and rocks and debris from various airplanes or vehicles have been observed in the vicinity. The airstrip has been used by pilots for years while the NPS has been evaluating whether it will continue to sanction its usage. It is located in close proximity to rising terrain, and the runway is only usable in a single direction. The airstrip is locally known as the "Chicken Strip." The pilot reported to the National Transportation Safety Board investigator that the wind was calm during his landing. The pilot indicated that during rollout he encountered a deep water erosion depression in the runway's surface. Thereafter, he lost directional control; the airplane veered off the runway, collided with a nearby rock, and nosed over. No mechanical malfunctions were experienced with the airplane. During the past 90 days, the pilot has landed at the airstrip approximately 6 times. The pilot opined that the runway's gravel surface had eroded due to rain runoff.