According to the pilot, the airplane was slightly high on the final approach for landing on the 4,300-foot long by 75-foot wide runway. He retained a slight amount of power for the flare, but the airplane impacted the runway and bounced. The pilot decided to go around after an additional bounce, and he applied full power and retracted the flaps incrementally from full flaps to 30 degrees, then to 15 degrees, and finally to 0 degrees. The airplane departed the left side of the runway and struck a sign, a taxiway light and a runway edge light approximately 2,300 feet beyond the approach threshold. It descended an embankment located approximately 65 feet from the runway centerline and impacted rocks. The Federal Aviation Administration inspector who examined the airplane noted damage to the firewall and the left wing. The pilot told the inspector that the airplane functioned normally, with no mechanical problems.