A long-time student of culture and its material artifacts, Karl has spent a substantial portion of the past five decades examining how and why people have created America’s diverse rural and urban landscapes.  His field- and archival-based research interests blend regional contexts, especially the Middle West, Appalachia, and South.  His past work included examinations of the relationships between European immigrants and occupational preadaptation, the social construction of sport and leisure places, the creation of landscape symbol vocabularies, and several projects relating to infrastructure, especially the spectacular role of the road—in its many guises and through its many commercial, political, and technical patrons—as a shaping influence on landscape making and change. Recent research projects include: The National Road and A Guide to the National Road, two edited books that were supported by funding from the Pioneer American Society and the National Endowment for the Humanities; The Great Valley Road: Shenandoah Landscapes from Prehistory to the Present, co-edited with historian Warren Hofstra, a book co-authored with historical archaeologist Nancy O’Malley, Kentucky’s Frontier Highway: Historic Landscapes along the Maysville Road, and two recent volumes Bourbon’s Backroads: A Journey through Kentucky’s Distilling Landscape (University Press of Kentucky, 2019), and Making Bourbon: A Geographical History of Distilling in  Nineteenth-Century Kentucky (UPK, 2020).