The term reservoir commonly refers to a body of water intentionally stored behind a dam for purposes of irrigation, power generation, ﬂood control, or recreation, or to supply communal drinking water; but it is also used as a synonym for an underground aquifer or a natural lake that serves such purposes. The Army Corps of Engineers has documented more than eighty thousand dams in the United States, but not all of them have created appreciable reservoirs. Historically, small reservoirs were often created in or near traditional villages. Massive reservoirs would include Fort Peck Lake and Lake Oahe on the Missouri River; Franklin D. Roosevelt Lake on the Columbia; Kentucky and Wheeler Lakes on the Tennessee; and Clarks Hill and Hartwell Lakes on the Savannah River. Man-made reservoirs have become common enough features now to be widely imagined as natural lakes. Another sort of reservoir exists in porous and permeable rock where oil and gas have accumulated, often under pressure. As Rick Bass describes the process in Oil Notes, “Suppose you have a gas reservoir or, say, one with gas and water, the gas ﬂoating and bobbing up and down above the water. You perforate a little too far down in your well bore and one day the water can’t resist: the gas above it is [already] ﬂowing to the surface, [being] pushed out into the pipeline, sold to the companies and shot out to the nation.” The Uintah Basin of eastern Utah, near Dinosaur National Monument, is an example of such a hydrocarbon reservoir, its oil and gas reserves being aggressively prospected by extractive industries. Most of these reservoirs, located as they are on the Uintah and Ouray Indian Reservation, could create a strong economic base for the resident Ute tribe. The physical invasiveness and the potential for social disruption generated by extraction technologies, however, have also stimulated requests from the Ute people for discussion and negotiation so that traditional tribal values will be taken into account in the planning process.