In the late 1970s, Southern California Edison Company proposed the construction of a 500 Kilovolt transmission line from Buckeye, Arizona (just west of Phoenix) to the Devers substation near Banning California. The proposed routes crossed the traditional territory of numerous Native American groups such as the Cahuilla, Chemehuevi Southern Paiutes, Cocopah, Mojave, Maricopa, O’Odham, Quechan, and Yavapai. As required by the National Environmental Policy Act, an environmental impact assessment was conducted to understand potential impacts this project could have on human and natural resources. For the first time since the passage of NEPA, Native American concerns were fully considered. This report presents the findings of the first Native American social impact assessment in the United States. This report presents contemporary Native American values that were pertinent to planning, construction, operation, and maintenance of high voltage generation and transmission facilities. The ethnographic study also considered the following aspects: (a) determine if, where, and in what manner such values were relevant to the Devers Palo Verde study area, (b) define differing levels of significance that Native Americans assigned to geographical points, zones, or issues within the subject study area exhibiting such values, (c) assign appropriate sensitivity ratings to the pertinent points, zones, or issues of significance and rank such points, zones, and issues from highest to lowest, explain what actions might constitute varying degrees, kinds of impact to those points, zones, or issues, and (e) provide recommendations for mitigation of negative impacts to those points, zones, or issues.