On June 22, 2018, about 1730 Alaska daylight time, a float-equipped de Havilland DHC-2 airplane, N5221G, sustained substantial damage during an impact with trees and terrain, following a loss of directional control during landing, about 53 miles northwest of Dillingham, Alaska. The airplane was registered to and operated by the pilot as a 14 Code of Federal Regulations (CFR) Part 91 visual flight rules personal flight when the accident occurred. The private pilot sustained serious injuries, and the three passengers were uninjured. Visual meteorological conditions prevailed, and no flight plan had been filed. The flight departed Naknek Lake, Alaska (5NK) about 1645. According to the pilot, he was landing with a tailwind on a remote river. After touching down on the water, the airplane bounced, and a gust of wind turned the tail of the airplane about 45° to the left. The airplane then impacted the river bank, continued onto the shore, and struck trees, which resulted in substantial damage to the airplane. The pilot reported no mechanical malfunctions or anomalies that would have precluded normal operation.