The private certificated pilot was landing on a gravel surface runway that was 3,000 feet long and 75 feet wide. The pilot said the sun was in his eyes, and he landed about 75 feet beyond the runway threshold. Upon touchdown, the main landing gear dug into soft sand, and the airplane received damage to the left main landing gear, the left aileron and flap, and the left wing. The pilot said that a postaccident examination of the runway surface revealed the first 100 feet of the runway consisted of soft, uncompacted dry sand.