[SunkenCiv]

The Smithsonian had a jackass named Alex Hrdlicka running it back in the first half of the 20th century (anyone reading this wanting to nitpick my not looking up exact dates or the exact name of the organization at that time get a preemptive GFY), during which period the Smithsonian loaded onto a barge a bunch of holdings that didn't fit the narrative, and dumped it into the Atlantic. Despite his treatment of precolumbian (and some post-columbian) human remains, he's been held up as some kind of hero for rejecting a priori any PreColumbian contact or transoceanic influence on North America.

[Smokin' Joe]

If you consider sea levels during ice advances, and the subsequent inundation of previously exposed (now offshore) areas of the Continental shelf, the area in the drowned river estuary where the axe was found was actually a promontory on an upland overlooking a fairly large confluence of valleys. Great spot for a village, or at least an outpost.

The exact location of that tower may not be available any longer because of development in the area, and because those who would recall where it was have passed on. Some significant tramping around might locate the footings, but they are likely obscured by foliage, and poison ivy there grows to the size of small trees.

It might be worthwhile to go back and look for more if I had the opportunity.

Then too, the area is one in which the site might be looted by some of the folks who live closest if it was identified, seeking something of value.