The species was rediscovered during a prairie butterfly survey in San Juan Island National Historical Park[2] in 1998.

The Island Marble is medium sized butterfly that is distinguishable by its white and green mottled pattern under its hind wings.

There are three known host plants for the Island Marble Butterfly: Brassica rapa, Sisymbrium altissimum, and Lepidium virginicum var.

[1] The Canadian Species at Risk Act (SARA) listed the island marble butterfly as being extirpated in Canada in May 2000 and again in April 2010.

[5] On August 22, 2012, the Xerces Society for Invertebrate Conservation submitted a petition for protection with the US Fish and Wildlife Service (USFWS).