Skiers and anglers arent the only visitors to pass through the Eastern Sierra. Every spring locals and human visitors alike can be delighted by the arrival of the butterflies known as the Painted Lady.

Besides showing up en masse as they pass through, you can spot the Painted Ladies by their orange wings with black spots. The tips of their wings tend to be black with white spots.

When not stuck in the grill of a car, billions of these butterflies take a long one-way journey each spring from the deserts of the Southwest and northern Mexico, to the Central Valley of California and beyond into the rest of North America.

John Smiley, the Associate Director at the White Mountain Research Station in Bishop says that after the adult butterflies hatch, many of them fly upwind and north toward the smell of new host plants on which to lay their eggs.

This flight brings them all over North America in spring and summer, where they reproduce again under suitable conditions. In some years billions of them come out of the deserts and everyone notices them; in other years there arent so many, Smiley says.

Dr. Art Shapiro an entomologist with UC Davis reports that the butterflies that can be seen in the Bishop area make it to Davis in the Central Valley in about three days.

While the butterflies show up en masse, smaller numbers return to the desert in a more spread out fashion. When the butterflies do slowly make their way back to the southwest and Mexico in the fall they can be seen in the Eastern Sierra as they stop to feed on the rabbit brush in October.

The Painted Ladies are also found in the southern hemisphere, making this one of the most widespread butterflies on the planet.