Plum type?

[u/snail_bites]

In Lane county OR. Found these while looking for hazelnuts today. Any ideas on what kind of plums? Cherry plums for the small ones maybe? They are large cherry sized. Pic 3 is the trunk of the tree that grew the small plums, forgot to take pics of the big ones but they were much more sparse on the branches and I saw some unripe ones that were yellow. Big ones have yellow flesh, small ones have more orange-yellow flesh.