Since oil wells first appeared in the territories of Colorado and California in the 1860s, oil and gas extraction has been an influential force in the American West. The modern western petroleum industry developed in surges of expansion and contraction during the 1920s, 1950s, and 1980s. Most recently, the so-called “Shale Revolution” of the 2000s ushered in waves of new and expanded production of dry and wet gas and oil, episodes that came shortly on the heels of a coalbed methane boom. There were 150,000 well completions in key petroleum-bearing geologic basins of the West and Northern Great Plains between 2000 and 2017; 40% were horizontally-drilled (IHS, 2018). From 2007 through 2017, unconventional oil and gas development (hereafter, UOG) in the West’s Niobrara and Bakken formations (found across a number of discrete geologic basins1 ) contributed 28% of United States shale oil production and 14% of shale gas yields (US EIA, 2018). A similarly booming social science literature has documented that these subsurface activities generate a mix of social impacts and outcomes for the people who occupy the diverse subsurface spaces and places above them. The local outcomes of UOG development range from a North Dakota community that rebranded itself as “Boomtown, USA” to Colorado communities that have attempted to ban UOG activities. This essay endeavors to review and synthesize among these varied spaces, places, impacts, and outcomes. The American West, defined here as the region of the United States located between the Pacific Coast mountain ranges and the 100th Meridian, features a number of distinguishing characteristics that enable and shape different patterns of energy development. The region is characterized by repeating patterns of high mountain ranges separating basins that contain thick sequences of sedimentary rocks. These strata host extensive reserves of oil and gas trapped in conventional and unconventional reservoirs and hold some of the largest coal reserves on Earth. This physiography controls climatic patterns responsible for solar and wind resources as well. At the regional scale, the West is made unique by the aridity of the climate; its spatial expansiveness; a settlement pattern in which pockets of extensive urban and suburban land use juxtapose an interior of vast open spaces and rugged mountain systems; the vitality, diversity and presence of contemporary indigenous populations2 along with the legacies of colonial conquest (Limerick, 1987; Reibsame and Robb, 2007; Wyckoff, 2014); the substantial amount of land and minerals owned and managed by the federal government; and the divergence of economic trends within the region (Gude et al., 2012). A set of persistent social issues emerges out of this setting and influences the local outcomes of energy development, such as: the importance and difficulty of accomplishing justice for Native Americans and other historically marginalized groups; the sensitive politics surrounding the allocation of scarce water resources; the challenge of protecting vulnerable ecosystems unique to the region; the challenges of distance or the social cost of space; and finally, the complications of accommodating conflicting social values about the region’s natural resources and their appropriate use. These distinguishing features and issues coalesce in unique patterns across the West to create distinct “impact geographies” that are the focus of this review essay. By impact geography we mean a spatiallybounded area that features a distinct constellation of historical, physiographic (including climate, geology and ecology), economic, and cultural factors that influence the nature of oil and gas development and the character and magnitude of its impacts on local people, ecologies and landscapes. We argue that given the great diversity in the targets, configurations, and processes of shale oil and gas development in the many places that host it in the American West (and beyond), the best way to organize a search for emerging patterns in its social impacts is to work with impact geographies as an organizing framework.