Deschutes River, Oregon. April, 14 2012
Oregon State University collection
Comments. This is the Oregon state butterfly. Pyle treats it as a separate species but some consider it a subspecies of either the Old World or Baird's Swallowtail.
Similar species. Oregon Swallowtail has a yellow abdomen with black stripes and a black dot at the bottom of the red tail spot. Compare with the Anise Swallowtail which has a black abdomen with yellow stripe and a black dot in the middle of the red tail spot.