In a sense the experience of our family with this stream recapitulates Betty's and my own rural childhood, both of which included swampy areas ( see previous notes on the Manitowoc Swamp ). The locus of Folly Mills on our property is far more than a simple channel. The latter is bounded by prominent natural levees behind which lie a number of abandoned channel ponds and a calcareous wetland that is fed by large artesian springs, and this wetland contains some of the rarest plants in the State ( see our Forests of the Central Appalachians Project ). It is in turn bounded on the northwest by a steep, rocky forested hill ( Mueller's Mountain ). The stream was an immediate attraction to our sons Don and Gus, who spent countless hours in it and exploring its life forms, which includes Muskrat, Mink, frogs and a great variety of shells and other invertebrates. As in my Wisconsin marsh, the stream and wetland are also home to large Snapping Turtles. On one occasion Gus made such a professional appearing collection of snail shells for a school science project that it was rejected on grounds that it could only have been done with adult help! For more than 25 years the only Beaver ( Castor canadensis ) we saw on Folly Mills was an occasional single animal, usually swimming downstream. But sometime after about 2002 a colony became active along the stream, building a small dam, a pond and lodges, and felling trees. Their dam resulted in splitting the stream into two branches ( distributaries ) downstream from it and raising the water table both up and downstream. The new branch provides additional habitat, especially in winter, for such birds as the Great Blue Heron ( Ardea herodias ) and a variety of ducks. We had always thought that Folly Mills was too strong and too much subject to large floods for Beavers, but they've done well for several years now, surviving the winters largely on the bark of young Green Ash ( Fraxinus pennsylvanica ), but under only moderate flooding. However most trees accessible to the Beavers here are various species of oak, the bark of which they don't eat. Is it possible that there were previous Green Ash-Beaver cycles separated by periods of no Beavers, in which this tree had all been consumed?