Look up maple tar spot.

https://ag.umass.edu/landscape/fact-sheets/tar-spot-of-maple

I agree. A very common maple ailment and one that is really only cosmetic in impact.

prairiemoon, in case you’re interested, there is a housekeeping task you can work on this fall that can go a long ways in preventing future outbreaks. After the leaves have fallen, collect and dispose them. Don’t use the leaves for mulch. The propagules that will cause this particular fungus disease are living in the spots and can spread to the new, emerging foliage in the spring.

It is never recommended that you try to treat the unsightly disease while active on your tree, but the removal of fallen leaves will make a big difference.

Thanks for all the responses. Glad to know it’s not some fatal disease. [g] It makes sense that it’s only the lower branches that seem to be affected.

Rhizo, we usually save all the leaves and pile them up for compost in another part of the yard. I was thinking I could just collect the affected leaves and get rid of them with the yard waste, but….too late. It was pretty windy and a lot of leaves fell yesterday. Plus we have a ground cover at the base of that Maple, that would retain a lot of the leaves that fall. Luckily it’s a very small percentage of leaves on the tree that have those spots…next year I'll do better with collecting them and getting rid of them.

Thanks!