Saving a red oak

[psyched123]

I have a red oak in my backyard that is showing a decline in the leaf cover. I think the cause is coming from an old wound and am worried about rot from the wound getting to the root. Looking at these pictures, do you think the wound could be corrected and the tree get back to health? If so, what would it take? Thanks much in advance!

 

[treeseer]

Can you get the rocks off the trunk so we can see what's going on?