It is found on the Pacific coast from northern Baja California to southernmost British Columbia, and inland to New Mexico and the Black Hills of South Dakota.

It prefers open woodlands and forest clearings, especially near permanent bodies of water such as ponds, but also urban parks and is occasionally seen in suburban areas.

Their appearance is quite similar to that of the western tiger swallowtail, except they are a white-cream colour or very pale yellow.

Eggs are laid singly on host plants which include members of the genus Ceanothus, including buckbrush, mountain balm, and mountain lilac, as well as red alder, ocean spray, bitter cherry, and serviceberry species.

Like most swallowtails, they have a red wishbone-shaped organ called the osmeterium, which pops out from behind the head and releases a foul odour to warn off predators.

As they pupate, they face upright, secure the tip of the abdomen to a branch with a silk thread, and hang freely.