In Caitlin’s LaBar’s words from her blog, Northwest Butterflies:
For the last few decades, lepidopterists in the west have been uncertain how to classify a variably-marked group of Celastrina (azure butterflies) in the Columbia River watershed. Until now, only two species were known in this area: Celastrina echo and Celastrina lucia. Individuals from east of the Cascades were often lumped with echo but some from Yakima and Kittitas counties were thought to be lucia. However, neither arrangement quite fit and some started questioning if there might actually be a third species involved. In the past 2-3 years, with the help of many regional butterfly enthusiasts, some breakthroughs occurred which I started investigating with two of our regional Celastrina experts.
See the article in the link below, LaBar, Pelham & Kondla, 2022: