This thesis investigates how the Bear River marsh’s protection became a national interest and a cause for conservation in the Progressive Era. The thesis documents how the marsh declined because of irrigation development culminating with an outbreak of avian botulism in 1910, and traces the long process to protect the marshland. The research focused on examining local water development patterns of the nineteenth and early twentieth centuries, ornithological research in the 1910s, and the national sportsmen’s conservation movement of the 1920s. Upon examination of these events, it becomes clear that a coalition of ornithologists, sportsmen, and policy makers worked together to institute change that affected the marsh. Through showing how groups came together in the past to work for conservation, this research highlights the important role that a coalition of groups can have in reshaping how a landscape is viewed and managed.