This thing turned up along my bank and I have no memory of planting it. Anyone have any clues what it might be?

http://garden.org/plants/searc...
maybe pumila
https://gobotany.newenglandwil...
or

Looks like a tree to me (too).

Ulmus for me, too. I get several every year I have to pull. I recognize them the minute they get their 1st set of true leaves and then they're out!

Yes an Elm for sure, could be American Elm

The leaves look rather narrow and pointy for some of the elms, and we're also looking at WA which I think is out of range for U. americana? Is it possible to get a picture of a representative leaf or two to check for uneven leaf "shoulders" and a close-up of the leaf edges (margins) to see if they are double-toothed? Detaching leaves and putting them on a sheet of plain white printer paper for the pic helps.

Here is a close up of a couple leaves - they are about 2 inches long. The whole bush/tree is only around 3 feet tall right now. I only noticed it this year, it's in the 'wild zone'. I would like to ID it and figure out if it's anything I want to keep or not. I don't know much about Elm trees, the only ones I've heard of around here are called Piss Elm and I'm not sure what they look like, but know they are considered a pest. (Sorry, but I couldn't find a more polite name for them and that's all I've ever heard them called.)

Thank you. I can't come up with anything closer than Ulnus pumila (Siberian elm) as Stefan suggested. The leaf bases aren't as assymetrical as other elms, and that is a characteristic of U. pumila.

Well thank you all for your help - I would not have thought to guess elm. I will now have to figure out if it's something I want there or not.

The leaves and growth habit kinda look like hophornbeam.
Which doesn't seem to occur out west, but google turned up reference to American hornbeam and European hornbeam in Washington state.

I went that route too initially, Stone, that's why I asked for leaf close-ups to see the serrations. The hornbeams have more "fringy" pointy teeth on the leaf margins than Lauri's plant, to my eye anyway.