This EIS evaluates the environmental impacts of a proposal by Dine Power Authority, a Navajo Nation enterprise, to construct, operate, and maintain a 500-kilovolt (kV) transmission line planned to deliver electric power from the Four Comers area in northwestern New Mexico across northern Arizona to a terminus in southeastern Nevada. The proposed project, the Navajo Transmission Project, was planned to be in service in the year 2001 and operate for about 50 years.