Parnassians are part of the swallowtail family (Papilionidae), but don’t look like the typical bold, black and yellow or white-winged ones. They lack tails and are mostly white, with black and red markings. If you can’t catch one fueling up at a flower, you can still observe them as they fly slow and close to the ground. Rocky Mountain Parnassians have alternating black and white rings on their antennae, and wings that are mostly white, with both wings usually sporting red spots, along with gray to black spots. They can be found from the mountains of California, Utah, and New Mexico north into the southern Yukon. The butterflies lay eggs on species of stonecrop plants (Sedum), which their caterpillars will eat next spring after overwintering as an egg.
Photo by: Glenn Marangelo on 7/6/21 near Florence, MT