The historic site is a Class II area for the prevention of significant deterioration of air quality provisions of the Clean Air Act.  It has no capability for monitoring visibility or air quality. The closest parks with monitoring capabilities are Capulin Volcano National Monument, Great Sand Dunes National Park, and Mesa Verde National Park.

The closest major stationary source of pollutants are the industries in Pueblo, Colorado, approximately 60 miles west-northwest of the site. This includes a coal-fired electric generating station and the Pueblo Chemical Depot southeast of Pueblo.

These days visibility is variable, with the Spanish Peaks not always visible to the Southwest. The Spanish Peaks were reported in historic documents as visible from the fort. 

Although the Clean Air Act gives Class I areas the greatest protection against air quality deterioration, National Park Service (NPS) management policies make no distinction in the level of protection afforded to any unit of the National Park System. Protecting air quality in National Park Service areas is reflected in the National Park Service's Strategic Plan. Progress in achieving air quality goals is one of the results-oriented measures used under the Government Performance and Results Act.