During our visit to Bayfield, WI, we saw many Tiger Swallowtail butterflies. In northern Wisconsin (and northern Minnesota) these are actually Canadian Tiger Swallowtails. In the southern part of these states you would see Eastern Tiger Swallowtails. The two species look very much alike with the main difference being the width of a black line along the edge of the hind wing. That line is not even visible in this photo.
From July 21, 2013 - Bayfield Insects and a Frog