In Oklahoma, further south of you, our elderberry hasn't started blooming yet.
Here is a good link showing pictures of the different varieties with some photos similiar to your photo.
It looks like elderberry to me. Are the blooms sweetly fragrant? Ours have just started to bloom around here this year, which is late. You could take the pic and a sample to your local county extension office and they can identify it for you positively. If it's a bush, not a vine, it's probably elderberry.