i note the dams. as someone who spent many formative years in oregon and washington, watching the salmon ladders (on dams), and driving to hoover dam, and grand coulee dam, and tonight googling the 150+ dams and reservoirs on the incomplete list of dams and reservoirs in california . . . does any water west of the continental divide actually flow to, and in the amount, dictated by natural geography?
i know it's not just west of the divide. the southeastern u.s. wouldn't be the same without the tva.
but nothing riparian west of the divide appears to be natural.
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.