Dan Mouer, as usual, makes an excellent point. Tar pits look like chacoal
pits, but in northern hardwood forests, there were similar kilns for
roasting chemicals, too. In fact, the latter days of charcoal foundry
fuels in PA were fueled, if I may make a pun, by hardwood charcoal
byproduct of these kilns. So hardwood forests might also have "charcoal"
pits that were not really primary charcoal, but charcoal as a byproduct,
kilns.