On July 12, 2008, about 0005 Alaska daylight time, a Cessna 150 airplane, N22563, sustained substantial damage when it collided with a ditch during the takeoff run from a remote gravel bar, about 20 miles east-southeast of Manley Hot Springs, Alaska. The airplane was operated by the pilot as a visual flight rules (VFR) local area personal flight under Title 14, CFR Part 91, when the accident occurred. The private certificated pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. The flight originated at the Fairbanks International Airport, Fairbanks, Alaska, about 2305, and no flight plan was filed. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on July 14, the pilot reported that he had flown to a remote lake to look at land, and was returning to Fairbanks, when he decided to land on a gravel bar in the Tanana River at dusk. The landing was without incident, and the pilot described the lighting conditions as somewhat flat, due to smoke in the area. During the takeoff run from the gravel bar, the pilot said the airplane was slow to accelerate due to the loose gravel/sand, so he aborted the takeoff. A second attempt to takeoff produced similar results, and the pilot again aborted the takeoff. He then positioned the airplane onto an area of grass, and attempted a third takeoff run. The airplane was rolling on grass and sand, and only accelerated to about 36 mph, so the pilot made a slight left turn to extend his takeoff area. The nose gear collided with an unseen ditch during the takeoff and collapsed rearward. In the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1) submitted by the pilot, he indicated that there was no mechanical malfunction of the airplane. In the "Recommendation (How could this accident have been prevented)" portion of the report, the pilot noted that he should not have landed on an unknown surface, and considered other options before the final takeoff attempt. On July 23, the pilot notified the NTSB IIC that an examination of the airplane by a maintenance facility revealed structural damage to the left wing rear spar cap, and damage to the belly bulkhead at fuselage station 27.92.