Question
The trunk on my sugar maple has turned black and the black is going up the tree.  In addition to the black there are holes about 1/4" in diameter all around and up the trunk.  They are not very deep.
The leaves look fine.   Northern GA

Answer
If the holes are in a line the holes are from a bird called a sap sucker (wood pecker). They make the holes and sap collects in the hole and insects come to the sap and the bird returns to eat the insects. I would spray an insecticide on the holes to kill and prevent insects form coming and the bird will stop coming. Any insecticide will do--bug B Gone or ant spray are ok. On heavily pecked trees in the spring a fungus develops on the sap and causes the bark to turn black. The problem with bird peck is it degrades the lumber. It will not kill the tree but needs to be prevented.