On August 13, 2000, about 2057 hours Pacific daylight time a Piper PA-28-180, N16411, owned and operated by the pilot, landed on rough terrain adjacent to runway 07 at the Nevada County Air Park, Grass Valley, California. The personal flight was performed under 14 CFR Part 91, and no flight plan was filed. The airplane was substantially damaged, and the private pilot received minor injuries. Visual meteorological conditions prevailed during the nighttime flight which originated from Reno, Nevada about 2010. Two airport employees reported to the National Transportation Safety Board investigator that at the time of the accident they were at the airport and were monitoring the local Unicom frequency. They heard the pilot broadcast that he desired to land. One of the employees broadcast to the pilot that the airport was closed by the Federal Aviation Administration (FAA) for nighttime operations due to tree obstructions. The pilot acknowledged the transmission and stated that he was low on fuel and that he intended to land. The Unicom operator-witness further reported that he suggested to the pilot that he divert to two other airports, which were about 15 miles away. The Unicom operator-witness further reported that the pilot continued his approach. The airplane lined up with taxiway Alpha (parallel to, and south of the runway) and corrected toward runway 07 when about 20 feet above the ground. Engine power was increased, and a left turn was initiated to return to the runway. The airplane touched down in rough terrain in between taxiway Alpha and runway 07. Thereafter, it slid in a right turn, finally coming to rest 3 feet to the south of taxiway Alpha and about 500 feet from runway 07's threshold. Under the Safety Board's direction, the airplane was defueled. Approximately 2 ounces of fuel were recovered from the fuel strainer. Eight gallons of fuel were found in the right wing's fuel tank, and 10 gallons of fuel were found in the left tank. The pilot subsequently reported to a Safety Board investigator that his airplane is based at the airport. Also, the pilot has a Grass Valley address. Days earlier he had arrived at the airport and the lights were functional. The pilot indicated that he was unaware of the FAA's issuance of a Notice to Airman (NOTAM) regarding the airport's nighttime closure. The airport's management reported to the Safety Board investigator that on August 11, 2000, it had ceased allowing nighttime operations in accordance with a directive issued by the State of California, Department of Transportation. The runway lights were turned off at night because of obstructions resulting from the presence of nearby trees. A NOTAM, dated August 11, was issued by the FAA through local Flight Service Stations that indicated the airport was closed at night. In the pilot's completed accident report, he indicated that upon departure for the accident flight his airplane had 25 gallons of fuel in its tanks. He also reported that upon approaching the Nevada County Air Park, he had been advised via radio that the (runway) lights had been turned off the preceding Friday. Regarding the pilot's familiarity with the airport, he reported that for the past 10 years he has been based at the airport and performed between 300 and 400 takeoffs and landings. The pilot indicated that, during the accident flight, there was excellent visibility (over 20 miles), and the moon appeared full. Additionally, he felt "comfortable" continuing the landing approach to runway 07, which has been routinely used for night landings during the past 5 years. The pilot further reported that the runway and surrounding airport environment was in clear view and the wind was calm. He believed that his airplane touched down on runway 07. However, almost immediately thereafter, it veered right exiting the runway, traversed rough terrain, and came to rest against a hillside.