This appears to be one of those variable, hard-to-identify crescents, most likely a field crescent or a mylitta crescent.
It's a little beauty!

Sherry

Most likely a Mylitta Crescent. Extremely common butterfly here in Oregon/Washington.

Also known as crescentspots. To see more of them, try thistles or goldenrod when in bloom.

Thank you so much! I went back to my Kaufmann guide and it sure looks to be a Field Crescent as the antennal clubs are blackish brown rather than orange in other western crescents. That makes the 14th butterfly species for our yard. Finally an ID....thanks again!

BN

It is possible your butterfly is a field crescent, however:

It would be out of its range, normally in the higher mountains of Washington. What is your elevation?

The Audubon and Peterson guides, and the Butterflies of Cascadia book by Pyle do not mention antenna clubs as an ID point for these butterflies. It is not the entire antenna club, but the mere tip of the club that varies in color and it is hard to tell in your photo the exact color of the tips. In the guide books I mention, there are photos of orange-tipped field crescents and brown-tipped Mylittas.

It is the well-developed brown areas on the hindwings that most guides use to ID the Mylitta.

Perhaps next summer you will see more of these. If the topsides of the wings are generally dark, it is a field crescent and if the wings are orangish, it is Mylittas.

It would be great if it is the field crescent because that is a much less common butterfly in Washington.