I don't think that coal are really worth the bother at this point, charcoal was cheaper to produce and in fact better to primitive iron smelting and if there was one thing North America didn't lack it was timber.
Problem: charcoal requires low-temperature fires to keep most of the carbon in. It was used by the Amazonian tribes to create
terra preta, but I'm unaware of it occurring anywhere north of that. Besides, there is a large amount of coal just waiting to be used in Iroquoia and surrounding territories, and it's somewhat easier to imagine how coal would be used in fires (a few stones fall in, or somebody puts it in for the lols) than charcoal being made.
That's not saying, however, that charcoal won't be used. It will once gunpowder is going to be produced. All the main ingredients for gunpowder (saltpetre can be made from urine; sulphur is easy to find or can be replaced by coal, according to Wikipedia; and charcoal is easy to find) can be found in Iroquoia. Don't worry, though; the Haudenosaunee won't be getting gunpowder before the Europeans arrive. It's going to be European prisoners or paid engineers who will teach the Haudenosaunee to make gunpowder.
I know this seems like an excessive resurrection, but rest assured I am writing a new segment now. As far as I am aware the cutoff period for a thread is six months, and I am within a month with this. Consider CFaL officially reopened. (The minute I wrote this, the thread reached view number 1337

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