On September 1, 1999, about 2030 Alaska daylight time, a tundra tire equipped Piper PA-18 airplane, N9130D, sustained substantial damage when it contacted brush during the takeoff roll from a riverbank on Clear Creek, at 60 degrees 32 minutes north latitude, 144 degrees 46 minutes west longitude, about 38 miles east of Cordova, Alaska. The solo private pilot was not injured. The flight was being conducted under 14 CFR Part 91 as a personal flight to spot moose. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed. The pilot told the NTSB investigator-in-charge (IIC) during a telephone interview on September 13, and in his Pilot/Operator report, that during the takeoff roll, the left wing contacted brush located on the edge of the river, and the airplane spun around. The right wing sustained substantial damage, and the right main landing gear collapsed. He indicated the winds were light and variable. The pilot said he had operated from the same area previously, but did not avoid striking willows during this takeoff.