This was done by rivers so the charcoal could be transported to the forge. Or if the iron smelter was built by the trees, then to transport the iron.
Iron production was shifted to The Colonies because too many of the easy trees had been cut down in England to make charcoal for iron production
In the area I’m describing, the forest, mines, and forges/furnaces were all in the same area; the rivers (in this case, the Hudson River) were used to transport the finished product/iron. The iron mining lasted until late in the 19th century (in NJ into the early 20th century); lower production costs, and higher supply of ore, out by the Great Lakes doomed the industry here.