Upperside of forewing has a mostly all white cell and black band along costal margin. Underside of hindwing has black veins. Males patrol near host trees for females. Eggs are laid stuck together in a row on a conifer needle.
Caterpillars feed in groups when they are young and move apart when they are older.
Caterpillars pupate at the base of the host tree after descending from the tree on a silken thread. One flight June-September. Flower nectar including rabbitbrush, other yellow-flowered composites, and monarda. Western coniferous forests. G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.