On July 23, 1998, at 1507 central daylight time, a Champion 7GCBC, N21262, operated by a private pilot, was destroyed when it impacted water following an inflight collision with power lines near Clearwater, Minnesota. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan. The pilot received minor injuries. The local flight departed a private airstrip near St. Cloud, Minnesota at 1415. In a written statement, the pilot reported that he was heading southbound at 75' agl while sightseeing over the Mississippi river when he impacted power lines in level flight. The power lines were unmarked and were not depicted on the current sectional chart, which the pilot had consulted prior to flight. The pilot added that the power line poles are obscured by trees along the shoreline, making them extremely difficult, if not impossible, to be seen in flight. In a telephone conversation, the pilot reported that the flight controls and engine were operating normally at the time of the accident. The Twin Cites Sectional Aeronautical Chart states, "CAUTION: This chart is primarily designed for VFR navigational purposes and does not purport to indicate the presence of all telephone, telegraph and power transmission lines, terrain or obstacles which may be encountered below reasonable and safe altitudes".