I am assuming the portage is done on a maintained road and horses and wagons would do the carrying
You would not carry anything by hand as the land is fairly flat around the rapids and available to horses (unlike the portage around the FALLS)
Lifting the wood with the tripod method, I presume they used, at both ends of the portage would stop damage and not be overly expensive as labor is cheap
Cut boards would be extremely valuable in Europe as they have cut down their trees over the years esp trees for masts and supports beams for huge buildings
but the rapids might have prevented such huge timber from being transported unless the tree was floated
it is fun to speculate
Ah and here we thought you were talking of pioneers who would have had no roads unless they built them. Nor any maintenance on the road unless the gouged the traffic for tolls. Roads are yet another reason for pulling stumps. Not only was there never a one size fits all solution, but there never was a time when every one did anything the same. Everything evolves, leaving some behind the time and others doing it first. But the first guys hauled as little as possible anywhere, and figured better ways where they could.
While much of Europe was deforested for farming in pre-Roman times, they learned to build with other materials, from wattle and daub for the poor, to stone for rich folks' castles. The Romans in colonial Britain built mostly of brick, and with imported Italian and French (Gallic) roof and heating tiles, and after they went home even the backward natives eventually figured out brickmaking again, though it took them centuries.
Toronto's a city of brick because it was surrounded by rich farmland, the trees were weeds and so the wood ran out very early. As
blackrock says raw wood's a local resource by it's nature, the farther you have to ship it the better whatever is already at the destination looks. We only ship what we do now because it's plentiful where we can cheaply machine the hell out of it and reduce it to ready-to-use little sticks and sheets. And we still buy more than we ship.
Some time after the last war, one of the old colleges at Oxford that was established in Tudor times discovered wood rot in the ceiling beams of its Great Hall. Theses were massive timbers several feet thick spanning a great width in one piece. They were already a couple of centuries old when they were cut for the Hall, and now the engineers and wood experts said they had only a decade or so left. While the engineers pondered mechanical fixes and the College Council pondered rebuilding entirely, underlings were tasked with seeing just how far the College would have to go to find any trees at all of that size.
They'd pretty much narrowed it down to an expedition to an east asian rainforest, when they got a call from the forester of the New Forest in England. He apologized for not answering the enquiry as he'd been been away, but yes, he did have some oaks of the size and age that were wanted. Trouble was they weren't actually party of the New Forest so, "You'll have to ask the actual owners, it will be a bit tricky digging out the actual records, because no one's needed to know exactly who to contact in the three hundred or so years since they were planted. They belong to some Oxford College who realized eventually they'd need to replace their roof beams, so they'd better have a plan". There are stories about Japanese forest management that are very similar, since they started managing their forests about the same time so they'd always have the wood they need.
Although we're doing better now than in the past, it's because we're learning from the Europeans and others how to manage a resource that isn't just some unwelcome growth to be burned off, or even cash-cropped by clear-cutting. It's only those pioneers who can be excused for looking at the trees and seeing weeds to cut not a valuable forest to preserve.