Recently, a growing awareness of the possibility of man-made air pollution degrading horizontal visibility led the Congress of the United States to amend the Clean Air Act. Part of these new amendments, Sec. 169A.(a)(3)(A), calls for a study and report to Congress to include recommended methods for identifying, characterizing, determining, quantifying and measuring visibility impairment in Federal pristine areas, such as national parks. The purpose of the study reported herein was to establish methods of measuring horizontal visibility, plus methods for measuring the vertical atmospheric optical air quality, and for quantifying the solar insolation environment. The purpose of this study also included the actual establishing of the baseline horizontal visibility, vertical optical air quality, and solar insolation at Stanton, North Dakota. This site was chosen because it is located in an area where extensive development of coal reserves is likely to take place in the near future. Therefore, establishing the current baseline conditions is necessary in order to determine the future impairment due to the development and utilization of the area's coal resources.