Close-up of a Two-tailed Swallowtail (Papilio multicaudatus) – Many of our yellow swallowtails can be commonly found out in the woods as well as in your backyard. Males patrol stream courses or city streets looking for receptive females. This is probably the largest species of Butterfly in North America, with spread specimens sometimes pushing 6 inches in wingspan. Photo by Glenn Marangelo on July 7, 2016 in Missoula, MT.