There are a couple of locations in Southwestern PA (Fayette County, Laurel Ridge State Park) that list American Chestnut as an introduced species - is this a bug or something that was done for a reason? As far as I know it still pops up from old snags in those places the same as anywhere else in Pennsylvania. Thanks!
Both Fayette County and Laurel Ridge State Park have that species listed as introduced on the Status tab of the species page.
If you think this is an error you can flag the taxon. It looks like it’s listed as native in Pennsylvania so something would seem to be a little off.