They aren’t there per se, but the Vikings (as Varangians and whatnot) used portages between rivers to get their ships to and from the Baltic / Black Sea during Byzantine times. Vaguely related, my guess is, they and/or others used the portage method to bypass Niagara Falls using rivers in Ontario.
https://en.wikipedia.org/wiki/Thor_Heyerdahl#Revision_of_hypothesis
https://www.azer.com/aiweb/categories/magazine/82_folder/82_articles/82_heyerdahl.html
https://cannorway.com/discover-the-land-of-our-origin/
amusing sidebar:
https://www.badassoftheweek.com/basil
Now see you may have fallen into the “Ship” mentality trap my friend. Could the Vikings float without a “Ship”? They didn’t know how to make and use smaller boats? Only Ships? Since they only needed an axe, drill, hammer, and small hand made foundry to build boats, they could not just leave one at the bottom of the falls and build a new one above the falls? Or just many smaller boats at the top instead of a Ship? Or steal local canoes and smaller boats when needed? Same with any short portage point? Just build another boat on the other side rather than portage a whole Ship?
The Vikings+Ship only is a subconscious mental trap. What would we do if we were so capable and adept at building any kind of boat of any size from raw materials found everywhere? The Vikings used smaller boats for fishing and river navigation at home, why not abroad? I think they were much more intelligent and adaptive than we give them credit for. They would not have chained themselves to a ship and limited their own travel abilities.
I have thought about this a lot since the president of the maritime museum told me in an email “They could not have navigated the great lakes because they could not get their Ship past the falls”. I thought “What?, they permanently attached themselves to a Ship and could not leave it or travel without that particular Ship?”. :)
Great links! Thank you! Is that last one you?