On September 4, 2000, about 2100 Alaska daylight time, a Piper PA-18 tundra tire equipped airplane, N3774Z, sustained substantial damage when it ground looped during landing on an off airport gravel bar on the Malozitna River, Alaska, at 65 degrees, 27.06 minutes north latitude, 154 degrees, 29.06 minutes west longitude, about 60 miles north of Ruby, Alaska. The solo commercial pilot was not injured. The flight was conducted under 14 CFR Part 91, as a hunter guide business flight. The weather at the time of the accident was clear, with calm winds, and no flight plan was filed. The airplane sustained substantial damage to both wings, and the empennage. According to the pilot, he performed a wheel landing, and the airplane's nose swerved to the right. He said when he applied the booster brakes, the nose continued to the right, and the airplane ground looped. The pilot stated he believed the right brake locked up. According to the airplane owner, the pilot was landing on a 1,500 feet long by 100 feet wide gravel bar, and attempted to stop the airplane quickly to make a short turnoff.