Location of the tree is roughly the middle of the lower peninsula of Michigan.
There are lots of saprotrophic fungi capable of doing this. That tree has a lot of problems for a fungi to bloom that pervasively. That one is a goner. Dead trees perform important ecological services however!
It looks like northern sawtooth fungus to me but do not take an internet sleuth's word for it.
yeah i'd actually recommend OP to report this to the local government, because they'll probably want to prune the branches off or in the extreme case cut it down entirely to prevent damage as it comes apart.
It's on the edge of the road by an intersection, so yeah probably should be handled
You would need some more close up pictures to get any sort of identification, there are thousands of species that grow on trees. Also if you know the species of the tree that would help.
Edit: From your photo it almost looks like it could be chicken of the woods, which is edible and quite tasty. But you would definitely need more close up photos of them to confirm.
FYI, for any folks untrained by an experienced mushroom forager: always always always assume it is poisonous and will kill you.
And not only kill you, but perhaps kill you slowly and painfully
To add onto that, by the time some toxins present themselves (as in you're feeling/noticing effects) it's already too late and fatality is imminent
Oh yeah no way I was gonna try eating this
Any of them. That tree is half dead.
That's supper, right there! Laetoporus, aka Chicken of the Woods (also Sulphur Shelf, for the color).
It's eating the dead/dying trunk. Conks of some kind? If it's near any building I'd cut it down.
Could be golden oyster
Are you sure these aren't insect nests?
I don't think any insect would have so many scattered nests of such varied sizes across a tree like this.
I admit I didn't get closer than this picture, I was on my way somewhere. But it was so shocking I had to stop and take a picture. That was last week.
I assumed mushrooms. And then was reminded today when I saw this article.