I live just on the out skirts of where the Burr Oak flourishes in my region. Oddly enough my GF has a large one in her front yard. It’s a literal fight to try and find these being we have a large population of critters that feed on acorns...and they attack Burr Oak acorns with a passion...and for obvious reasons! These acorns can get literally massive, up to 2 inches long and big around as a half dollar. Just thought I would share.