This dissertation traces the history of cattle grazing at Saguaro NP, Organ Pipe Cactus NM and Fort Bowie NHS in southern Arizona. This collection of studies examines the factors affecting that use, the ranchers who made their living from the landscape, and the federal land managers responsible for sustaining the natural and cultural resources. A dominant industry on arid public lands since the Civil War, grazing was altered by a variety of influences: environmental and human-derived. Ranching communities developed from homesteading settlements. Success was determined by climate, topography, and natural resources; social and cultural pressures; economic events and political legislation; and later federal regulations and decisions. The first agency to oversee grazing, USFS was under constant pressure to maximize short-term human benefits. The NPS Organic Act of 1916 mandated conservation of natural resources "by such means as will leave them unimpaired for future generations" and yet approved cattle grazing, an extractive use, under USFS management. Park managers were frustrated by grazing practices not under their control. Parks were at a cultural and social disadvantage. Residents and politicians often expressed displeasure at park reservations; communities feared that parks would interfere with local industries. Park employees supervised visitors and developed recreation infrastructure; they came with little experience to manage livestock. Lack of funding for research, limited manpower, and political and administrative interference allowed cattle grazing to continue unregulated for decades altering vegetation and enhancing erosion. In the 1960s, changing values from the environmental movement, the waning power of the livestock industry, and the rise of activist scientists impelled NPS to act. Without monitoring data, NPS turned to legal opinions to terminate grazing. Now grazing is regulated and carefully monitored. NPS is mandated to incorporate research results into management decisions. Older grazing permits are being retired, but land acquisitions for park additions add new management challenges. Purchasing permits offers a new but financially limited opportunity to protect sensitive lands. Grazing has ended at all three parks, yet ecological changes and historic structures remain. As cultural and administrative legacies, those remnants offer opportunities to interpret a significant regional tradition and an untold controversy.