First of all, there is a maple tree with naturally yellow leaves.  It is named Princeton Gold.  It is a beautiful tree.  Especially when the sun hits those leaves. It may be that is the variety of your tree.  Also, don't worry about the galls.  You can't prevent them and they are only cosmetic.  Some years there are a lot.  Other years few to none. They are caused by a small insect laying an egg on the leaf.  I would like you to do two things. First take a soil sample and have it tested. I will give you a link to our lab. Secondly, while you are taking up soil for the sample, I would like you to dig down and take a look at the roots. Your maple should have a definite flair at the base. The photo is far away but I cannot see it. If the tree is planted too deep it will develop stem girdling roots which will gradually kill your tree. The first real root coming out from the trunk should be just barely below the surface of the soil. If it was planted too deep, false roots will have sprouted out from the trunk and, not being real roots, go in a circle. Eventually as those roots grow and the trunk of the tree grows, the girdling roots will cut in to the trunk cutting off nutrition. I am also going to give you a link to that information.  http://soiltest.cfans.umn.edu/     https://www.michigan.gov/documents/dnr/StemGirdlingRootsUndergroundEpidemic_198244_7.pdf

Thank you, Barbara. I appreciate all the information. I will test the soil and check for stem girdling roots, and follow up with you when I have that data.

I mailed a soil sample for testing. I also looked at the tree roots. I dug 6" deep in an 18" diameter area around the base of the tree. See the three photos. The dark area of the tree trunk is the portion that was covered by dirt, with the top 1" being mulch above ground level. Approximately 2" below ground level, on one side of the trunk, is a 3/4" diameter root tightly pressed against the trunk (photo 1, from above). Photo 2 shows the side of the trunk with the tight root does not have any flare compared to the other side. Photo 3 shows the opposite side of the trunk, where a large root goes down from the trunk at 5" below ground level. Other roots I see there simply circle the trunk a few inches from the trunk. Would you agree the tree has at least one stem girdling root and was planted too deep? What are my options?

Good work!  Yes, it was planted too deep.  You can correct that by keeping the soil pulled away down to just above that first root.  You may have to make a fairly decent size ring, maybe kept in place with edgers, and then some organic mulch maybe 2" deep to cover the soil.  That will look like you originally planned it.  The stem girdling root can be cut.  I believe there are instructions in the SGR link I gave you before.  You can cut a chunk out of it and pull the root away form the trunk if possible. If you cannot pull it away, at least it will not longer continue to grow.   You have saved your tree. Congratulations!

Thanks, Barbara. I removed the stem girdling roots and modified the soil level around the trunk. Hopefully that will encourage a healthier tree in the future. When I receive the results of my soil test, I'll follow up with you to discuss.

You do good work!  FYI on the same page where you ordered your soil test, there is an area where you can get your results explained.  We can only hope that others in the area with the same problem handle theirs as well.  Happy Fall.

OK, I see the soil test interpretation guidance on the website. Thanks again for helping me and my tree. Happy Fall to you, too.