Hi Chris, Kimberly here from landscape-solutions-for-you. Thank you for asking the question on the problem you are having with tree roots above ground. This can be a common problem with mature trees, and certain varieties.
There are a couple of things you could do. With my clients, I have recommended two solutions. One is to bring in fill dirt, about six to eight inches. You can level out the fill dirt and put mulch, pine straw, or decorative stones aroud the tree.
The other idea that many people like is to have a raised bed around the tree or trees. You would still bring in good quality top soil, between six and eight inches. Level it out and plant some shade shrubs or flowers around the tree. This will take care of your root problem, as well as ehnhance your yard. Organic mushroom compost added to the soil will help your plants develop their root system. There are many different plants that will do well in shade or partial shade in your geographic location. If you decide on doing this, I would be happy to give you suggestions on different varieties you could use.
I hope this information is helpful and the best of luck to you. Thank you again for asking the question and best of luck to you. Feel free anytime to ask a question here at landscape solutions. Have a great day!
Kimberly