Ok here is another one for you. I have this tree growing in my yard. It's been there for about three years now. Every year it grows straight up about 3 feet. It grows a bunch of branches out the top of the main shoot. Each branch has about 17 smooth green leaves, one across from the other one. With a leave at the end. The branches turn yellow and fall off every winter. It does not flower and has not grown any fruit on it as of yet. When the branches fall off the main the main stem, it leaves a kinda upside down triangle. If anyone has any ideas please let me know. Thanks!
What you are calling "Branch" and "Leaves" are actually a single leaf, a pinnate, compound leaf.
The 'Branch' is the rachis, like the main rib of a leaf, and the 'leaves' are actually leaflets.
Anyway, Ash trees (Fraxinus species) will shed leaving a noticeable scar as in your pictures.
There is an Ash native to Oregon, and there are several species of Ash grown as shade trees. Most Ash will readily reseed, and the seeds can sail through the air for surprising distances.
Look up Fraxinus latifolia for the native.