Wild fruit tree ID?...... possibly buckthorn

We may have mistaken this for a chokecherry, but the berries seem to be on the tree rather late.  Location is north Central US about 200 miles south of Canadian border.  Thoughts??...Thanks!

Looks much like the common buckthorn I see growing all over here. Not very good fruit for us but the wildlife seem to use it regularly.

I considered buckthorn as we certainly have a lot of that around here.  What seemed different from that species is that our buckthorn typically has pretty dark green leaves and are not at pointed....usually more rounded at the tip.  The growth habit of buckthorn seems a bit different to me as well....more large shrub-like where this is somewhat plum/prunus-like.  I'll scout around tomorrow for something that I know is buckthorn and may post some follow-up comparison shots....Thanks!

Try cutting one in half. If it's a cherry it'll have a single pit instead of multiple seeds. There are more than one kind of wild cherry trees. Does it smell like cherry? I'd guess common buckthorn is probably correct.

The veins running parallel down the leaves are a buckthorn thing.  Try Rhamnus catharticus or purging buckthorn, which by its common name doesn't sound very promising!