https://www.youtube.com/watch?v=CiqK4mLrCZo Location:Flapper valves visible under road; remnant dykes visible in marsh. N 44°37’05” W 67°44’55” Geology:Salt Marsh: Dykes north of the road were constructed in the 19th century. The dykeing technique technique came from the lowlands of northwestern Europe. This method was used to desalt the marsh grass (hay) so it could
