Trunk of sugar maple.
It is quite normal for an older maple to have rough bark and for some of It to peel. As far as the sap, we need to see a photo and have more information. Was a branch lost at that point? Is there a sunscald crack? If your tree happens to be a silver maple, and not a sugar maple, the bark will peel off in large chunks as the tree gets older and older. We need a photo and more information to be more precise.