Two-Tailed Swallowtail Bracelet -- Papilio multicaudata
The second largest butterfly in North America. These are quite a sight!
This common, large butterfly, is common in the dry desert regions in Eastern Washington and Oregon south into Mexico. The larvae feed on Chokecherry, and also ornamental Ash trees.
There is one main late spring/early summer flight in Oregon, with a second smaller flight in mid-August.