How historians and preservationists define historical significance and recognize historic sites changes as history happens and as new research becomes available. Middle Tennessee State University Center for Historic Preservation director and professor Carroll Van West offers his perspective on how Montana’s grassroots preservation movement has changed over the last forty years in "Extending Historic Preservation’s Grassroots in Montana: The Resource Protection Planning
Process, 1983–1986." Van West’s presentation looks back on images he captured in a 1980s planning survey alongside his images from the last seven years, revealing what he missed and highlighting issues that shape preservation efforts today