In New Jersey there was a plank road running down the back side of the Palisade cliffs down to (and across?) the marshes. My father who was born in 1909 talked about it as if he had seen it, but perhaps he was just repeating stories he was told.
The road was washed out several times by the natural water flow through the swamp.
It was eventually replaced by a gravel road in 1838 but that also was prone to being washed out.
Finally in the 1850s the effort to drain the swamp began in ernest and roads became more permanent.
I can believe it. I did a job to locate how far and deep a cordoruy road was in a Seattle suburb. The existing road was only a couple feet above the old road, I’m guessing the timber road was from the early 1900’s up until the thirties or later.
Hmm. My mom and dad (born 1916 & 17) would talk about the “wash board” roads by our cabin. I always figured they meant just how rough the dirt roads would get. But many of them went through swamps. I wonder if early on they were cordoruy roads - so were REALLY like washboards?
BTW - I think when they built the Alaska Highway where there were parts where they would lay down large trees (2’ plus diameter) and the next day they would be gone in the muck!