Oak tree is dying
Thank you for the question. Your oak tree appears to be suffering from advanced oak decline. I can't tell what has caused the decline but the apparent death of outer branches, tufts of leaves on the branches (called epicormic growth), and your description of trouble for years are all symptoms of this problem. The tree probably cannot be saved but you could have a certified arborist evaluate it for you. Learn about oak decline and how to hire a qualified professional in these publications:
https://sref.info/resources/publications/managing-oak-decline-1 Click on the pdf on managing oak decline
Thank you for contacting Extension.