These special butterflies, endangered or threatened across much of their small range, have their stronghold in the state of Missouri. These images were taken in St. Francis Co., MO.
Swamp Metalmark – Calephelis muticum
"What a thousand acres of Silphiums looked like when they tickled the bellies of the buffalo is a question never again to be answered, and perhaps not even asked." -Aldo Leopold
A Thousand Acres of Silphiums 
Glad you were able to relocate this species – fantastic images, Bill.
Thanks Miguel!