This chapter discusses the perspective of the Edison Electric Institute (EEI) concerning visibility protection in Class I federal areas (principally, our large national parks). I will focus on EEI's general approach to environmental planning, the provisions of the Clean Air Act that protect visibility in mandatory Class I federal areas largely from existing sources, the Environmental Protection Agency (EPA) regulations that provide that protection, the prevention of significant deterioration (PSD) program that is designed to protect visibility in the Class I federal areas from the adverse impacts of new sources, and EPA's regulations to implement that statutory program.