During the late nineteenth century, American industrialization, the expansion of railroads into the West, and the rise of large corporations led to the widespread destruction of areas of the Plains, as well as increased pollution of land and water. In response to these threats, a complex environmental movement emerged, supported by President Theodore Roosevelt. John Muir, founder of the Sierra Club, advocated preservation of natural resources from use, while Gifford Pinchot, a forester, called instead for conservation, the proper use of natural resources. Together, environmentalist advocacy of different types led to the establishment of the National Park Service by Congress in 1916, and the preservation of areas including Yosemite and Yellowstone. The government documents, photographs, films, and passionate appeals presented here allow one to answer the era’s critical questions about the environment. How should it be maintained? Who should take responsibility for its care?