Common Ringlet as the most likely, given the choices in San Louis Obispo County. If it is, it's a very pale form.
Lorquin's Admiral. Note the orange wing tip that extends down the edge of the fore wings, and the pattern of white bars.
California Sister. Note the orange on the wing tip is confined to a dot, and there are less white markings.
Acmon Blue or Lupine Blue, based on the orange marks on the hind wing. This was easily the smallest butterfly I have ever seen, even smaller than the Eastern-tailed Blues back east.