Burr Oak Doesn't Look Good
Woodpeckers are looking for insects under the bark and rotted wood. It looks like the central leader of the tree has lost its leaves. Some pruning is probably necessary. To diagnose the problem a certified arborist should look at the tree. They can also check for disease. There is a serious disease of burr oak in MN.
May we use acorns from this tree to plant another one, or are the acorns adversely affected too?