Looks like an autumn blaze alright. Would suggest using Acer rubrum instead to save you the headaches. Just about every one of those I see has a cracked or damaged trunk to some extent.

When was the deck put in?

I ask because the tree is quite close and could have lost a number of roots. Among the causes perhaps severed roots, soil compaction, and/or raised grade.

The deck was there before the tree. No severed roots, soil compaction, and the grade has never been raised. I know these things could add to tree decline, but I'm looking to know more specifically what is going on here. As you can see from the overall pic, the tree has been a very healthy and vigorous growing tree. Then within 2 summers it's completely girdled with bark rot. I know little things add up, but I think this is something more than that.

how high is the mulch at the trunk???

was it potted at planting??? was it professionally planted???

was any effort made to insure that the roots grew out away from the trunk.. rather than around and around????

i suspect a severely rootbound potted tree that was not unwound .... and Maybe planted to low.. then perhaps a mulch volcano .... perhaps planted in clay ....

pure speculation .... any further info per above might get us somewhere ...

go for oak .. some actually think.. they grow faster than maples ....

ken

The mulch is at the root flare, and it has never had a volcano of mulch around it. Mulch has never touched the places where the bark decay started. It was potted (it was very small when planted), and I consider myself just as professional at planting trees as any other "professional":) No, it wasn't rootbound,but regardless, the root mass was separated and spread out when planted. When I first began inspecting this tree in the spring, I dug down a few inches around the trunk, looking for problems but everything looked healthy and the major roots had a nice spread going away from the trunk. As far as clay, I consider the soil there to be low clay content. I would suspect some of these things if the growth had been stunted or if had looked unhealthy over the years;but it has been a perfect specimen until now. Nary a wilted, scorched leaf or limb dieback; excellent green all summer and the brightest red you can imagine in the fall.

sounds like you did EVERYTHING right ....

and i am going to throw out more thoughts.. dont take them personally ... just stabbing in the dark here

that is one perfect lawn ...

was it resodded recently??

how do you maintain it weed free???

was the mulch ever black.. instead of red ???

is there plastic under the mulch???

is the damage on the side of the prevailing winter winds???

ken

No, the lawn has never been sodded. And it's not quite as weed free as it may look in the pics. He does use a one time Weed'n'Feed every spring, but other than that they just pull weeds in the vicinity of the gardens to keep it looking good. Mulch as always been red, and there has never been any plastic or fabric under the mulch.
I know I didn't get a pic of every side, but the bark is missing all 360 degrees. It looks just like it does in the 4th picture all the way around. The small strip of bark that is showing in the one pic is now gone. It was the only remaining live tissue, but a couple days ago I examined it again and under that strip was just black, mushy rotten tissue. So now it is completely girdled by a 3' strip of missing bark. I am amazed at how fast it happened. Also, the deck and the house are the west and southwest side, so it has had protection from the worst winds.

You wrote :"I am amazed at how fast it happened. "

I doubt it happened rapidly.

Instead, the underlying wood died over an extended period which, in turn loosened the bark. The bark coming off was what was "rapid" but, again, only after an extended period as the cambium died.

No, it was pretty rapid. Sure, some of it probably began over an extended time.....Since coming out of dormancy this spring, the bark has been trimmed back 2 or 3 times to the living cambium. I performed this operation and was very carefull to make sure to only leave living cambium. I would mark it, and check everyday for growth or swelling. It would begin growth, then suddenly one day it would be black and crumble off the tree like a dried fungus. It only started as 3 or 4 openings in the spring, and kept spreading.
I've cared for trees for a long time and I've never seen anything like this before. Anyone ever dealt with a fungal canker that spreads? Even though no one has mentioned it, I'm still believing it has to be something like that.

I had a very similar problem 2 years ago. My tree was an October Glory, and the trunk damage looked almost identical to that. I had a local arborist examine it and give recommendations. He said it was a "diffuse canker", just like you are thinking. I can't remember the scientific name he gave to it, if I look through my papers I can probably find the diagnosis report that he wrote up. Just like your experience, it started showing up visibly one summer, appeared it was closing off the damaged areas, then the next summer it was like a flesh eating bacteria or something. I know that sounds crazy, but just when new cambium tissue began growing, it would turn black and die. Kept going until the tree was girdled. This tree was 12 years old at the time. I cut it down later that summer. If I can find that name, I'll write back.