A Juniper or, maybe, a Cedar Hairstreak!
After spending a few hours trying to determine what the name and subspecies of the butterfly it seems that it is Callophrys gryneus, ssp. plicataria. The older name C. g. barryi is now a synonym. This was determined first in 1976 and confirmed in 2012. As for the common name… take your pick! By the way, they like daisies.
"Callophrys gryneus", the juniper hairstreak or olive hairstreak, is a butterfly native to North America. It belongs in the family Lycaenidae.