Trying to ID this tree, which grows in Colorado Springs, CO.

We could guess but need more information to make a definitive id. Can you get photos of the whole tree, the twigs and especially how the leaves are attached to the stems.

Maybe it's ash or sumac but this is just a very tentative guess. As KellyFW mentioned, we need more info if possible.

I think ash has a terminal leaflet. We need more information.

porkpal said:I think ash has a terminal leaflet. We need more information.

That rules out ash then. Does sumac also have a terminal leaflet?

From the difference in size of the two terminal leaflets I wonder if one other leaflet went missing or if the leaf developed abnormally. Pics of more leaves would show whether it's typical not to have a terminal leaflet or it's an anomaly.

Thanks for the extra pictures. With opposite leaves and a terminal leaflet that makes it an ash tree.

I agree.

Ash.

Thanks everyone.