These little butterflies -- I'm pretty sure they are pigmy blues -- are extremely common in the eastern Sierra Nevada, where the adults feed on a variety of flowers.   These are mainly on buckwheet (Eriogonum).   Like many butterflies, they usually perch with the wings tighly folded, making it difficult to get an image of the upper wing surface.   I took these pictures with a macro lens and on-camera flash along Convict Creek, Mono County, California.