[Sacajaweau]

Betting not privy but a Smoke house...pieces of coal were found.

[mass55th]

If coal was found, there should have been evidence of burning in the layer of dirt it was found. The owners may have just thrown the ashes of their fireplaces/cast iron stoves out in the privy.

[TXnMA]

Have you ever smelled the noxious smoke from a coal fire?

Coal was hardly (if) ever used for smoking food. Almost any wood would have produced better-flavored smoked food...