Mystery tree in the Ozarks... Help!

Hello from the Ozarks! I found several of these while gathering wild blackberries and needed some help with identification. Thanks!

American Plum maybe.

I think you are right! I was a bit thrown off because the only other plum I had previously found on the property was a young little guy with one almost-ripe plum on it. I didn't know that the ripening period for Wild Plum's in Arkansas could be anywhere from June-October. I found out that there are five native plums here and they hybridize so it makes them difficult to identify. Thanks for the help Dave!

yum plums

now go find some pawpaws on the place next

loads of paw paws here along the river. i tried them once but very bland. the indiana banana. lol