A tree in the lower Ledges State Park is a veritable "timeline." On its side are recorded the flood levels in the park's many inundations: 1954, 1957, 1965, 1979, 1981, 1983, 1984, 1990, 1991 are years visible on the tree. The Des Moines River also flooded the park in 1993 and 1996. Dr. Louis H. (L.H.)Pammel, Iowa State College professor of botany from 1889-1929, predicted that if the Des Moines River were ever to be dammed (which it was in 19??), the Ledges would flood frequently. The repreated flooding has radically changed the appearance of the lower Ledges--the timbered areas have been greatly reduced, is often covered with silt and, in general, looks devestated. This is quite a change from the time when Farwell Brown and his fellow Boy Scouts camped in the Ledges in the 1920s among the lush growth in the lower Ledges. The gentleman by the side of the tree is believed to be one of the park's rangers.