Bur Oak, large, long lived tree.
Common throughout Iowa and lives a long time usually, see below.
Bur Oak Blight is becoming common on bur oak trees in Iowa. It does kill them. In the above picture the one on the left has a bad case, the one on the right is just starting and the one in the middle shows no symptoms. Dead leaves hanging on branches in the winter is a good indicator of this disease starting. Our Swamp bur oak has been shown to be resistant to this along with the swamp white oak.