In addition to the additional photos of varying quality, this individual (and conspecifics) were nectaring on the willow buds of what my have been Arctic Willow or a closely related plant. This plant was only, literally, inches tall and covered portions of the "alpine" hillside above treeline.

Hope that helps. This is fascinatingly educating!

Might also be a Mountain Fritillary (Boloria napaea).

This is a Boloria freija. See image of close up underside here: http://www.nearctica.com/butter/plate14/Bfreija.htm

Comparison of other Bolorias here: http://www.nearctica.com/butter/plates/nymph3.htm

Here is a character that helps nail down Boloria (or Clossiana if you prefer) freija. If you look at the photo of the underside, and look at the underside of the hind wing, you will see a prominent white spot near the base (it is just peaking out from the flower here). This mark is stretched outward along a vein to connect with a roughly "w"-shaped white mark. Combine this with the roughly arrowhead-shaped white marginal marks, and you can usually get this one at a glance. This pattern is very characeristic of this species (occasionally the connection of the basal white spot is not quite complete though but there is a "stretch" to almost complete it regardless). The same pattern occurs also (if I remember correctly) only on the very closely related B. natazhati, which is more of a dark chocolate-colored Alpine species. If you have only the upper side, it's a little more difficult, since a few others are very similar. http://www.cbif.gc.ca/spp_pages/butterflies/species/BeringianFritillary_e.php