This article makes it sound as if there's no large American Chestnuts, but that's not completely accurate. The largest trees in the US are a pair of trees in Thurston County, WA, that are 80-90' tall with ~10' circumferences: https://d3f9k0n15ckvhe.cloudfront.net/wp-content/uploads/202...
IIRC, they do grow, blight free in the West. However, anything in the Appalachian range, (this species' native habitat?) dies from blight pretty consistently. Lost 4 billion trees in 40 years.
Edit:
https://en.wikipedia.org/wiki/Chestnut#North_America