Southern Wisconsin Butterfly Association (an outstanding group of people, btw, for any locals who might be interested. See this link re future field trips).
We met on Monday at the Bauer Brockway Barrens, a Wisconsin State Natural Area, and explored for several hours. Although the countryside looked thoroughly uninviting (notice "barrens" in the name of the location), the trip yielded an impressive list of the sightings.
I was happy to capture the above image of a "Karner Blue" (Lycaeides melissa samuelis), which is listed as a Federally Endangered species. The butterfly, originally identified by Vladimir Nabokov, relies on wild lupine as a food plant for its caterpillar.
The lupine in turn requires requires a barren, prairie, or open savannah setting because vigorous tree growth shades out the plant. Wisconsin has more Karner Blues than anywhere in the world. The individual in the photo was unusually cooperative in holding still for its portrait, but only showed me the underside of its wing. The top of the wing sports the remarkable blue from which the group derives its common family name.