Following the end of the Civil War and the development of railroads linking western states and territories with eastern markets, the livestock industry in the western U.S. began a massive expansion. Throughout the late 1800s, livestock grazing developed into a hugely profitable business, drawing investments from eastern cities and even Europe. These investments resulted in a huge growth of western livestock herds. These herds were largely dependent on public lands for forage resources. By 1884 there were an estimated 40 million cattle in the western states, with an estimated 1.5 million head of cattle in Arizona alone. The semi-arid ranges found on the public lands of the western U.S. were not capable of supporting such large numbers and this resulted in large scale overgrazing. This era would ultimately end in both catastrophe and promise for the future. Repeated droughts in the 1880s and 1890s, and the extremely harsh winter of 1886-87, caused the death of millions of cattle and left vast areas of eroded and bare soils in their wake. 

However, this ecological disaster also had a silver lining: ranchers and government agencies recognized the need for regulations to prevent over grazing of public lands and, as a result, the new science of rangeland ecology and management to improve our understanding of rangeland ecosystems and prevent similar outcomes in the future.