I read an interesting book which pretty much showed that none of the New England landscape was ever “natural,” not even when the Pilgrims landed. The Indians farmed, cut trees, burned sections to plant crops, and so on.
And in the early years of white settlement, almost all of the streams and rivers were manipulated. The rivers were needed for travel and commerce. The streams were used for water supplies and for water mills, which were the main source of power for such things as grinding corn and wheat or sawing lumber. Streams were redirected all over the place, swamps were drained, dams were built, ponds were created.
There is no such thing as pure nature, anywhere. And if humans don’t do it, animals will—beavers, deer, buffalo, you name it.
thanks for your input. i've driven over hoover dam. i've backpacked by beaver lodges. beaver don't coordinate with other beaver to set up a state-wide or national water flow/retention plan. so i understand, but think there is a difference of scale that makes my question/observation relevant.