Elfin for sure....I'm not sure what else you have in your area but it does not look like a Bog to me. I would say it looks like a Eastern Pine Elfin - Callophrys niphon. (yours has the two dark marks on the lower portion of the fore wing and the markings on the back of the hindwing are very distinct where they would be diffused on the Bog...some guides have little arrows pointing to the differentiating features....) Nice find! Rarely seen but the timing is right.