Night Skies: A Wilderness Value

A man shown in silhouette against a brilliant night sky sits in contemplation of the galaxy from his rock perch at Yellowstone National Park.
A man sits in silhouette against a brilliant night sky in contemplation of the Milky Way from his wilderness perch at Yellowstone National Park.

NPS / Neal Herbert

In wilderness, we preserve more than outstanding opportunities for solitude or a primitive and unconfined recreation, we also preserve complex ecosystems and landscapes where modern human influences, and permanent developments are minimal. However, recent research shows that between 2011-2022 there was a decrease of 10% on average in the amount of stars people across the globe could see every night (Science, 2023). Unlike other forms of pollution, light pollution is a problem with solutions that are easy to implement, and deliver immediate and lasting results, such as solutions in the NPS Sustainable Outdoor Lighting Principles page.

The Wilderness Act established a National Wilderness Preservation System for “the permanent good of the whole people” and the law’s primary mandate is preservation of wilderness character.”Dark night skies are part of a park’s wilderness character. Wilderness character is a holistic concept based on the interaction of (1) biophysical environments primarily free from modern human manipulation and impact, (2) personal experiences in natural environments relatively free from the encumbrances and signs of modern society, and (3) symbolic meanings of humility, restraint, and interdependence that inspire human connection with nature. Taken together, these tangible and intangible values define wilderness character and distinguish wilderness from all other lands (Keeping it Wild 2, 2015).

There are five tangible qualities of wilderness character that have been derived from the Wilderness Act.

  • Untrammeled Quality: Wilderness is essentially unhindered and free from the intentional actions of modern human control or manipulation.

  • Natural Quality: Ecological systems are substantially free from the effects of modern civilization.

  • Undeveloped Quality: Wilderness is essentially without permanent improvements or the sights and sounds of modern human occupation.
  • Opportunities for Solitude or Primitive and Unconfined Recreation Quality: Wilderness provides opportunities for solitude or a primitive and unconfined type of recreation.
  • Other Features of Value Quality:Wilderness may also contain ecological, geological, or other features of scientific, educational, scenic, or historical value.

These tangible qualities complement possibilities for natural lightscapes, and therefore an environment that is not impacted to the greatest extent possible by artificial (human caused) light pollution at night. In a culture where electricity is available, the excessive and uncontrolled use of outdoor lighting may become prevalent and an environmental problem, for humans as well as wildlife.

The 2006 NPS Management Policies, Chapter 6; NPS Director’s Order 41; and the NPS Reference Manual 41 all provide guidance for preservation and management of the wilderness resource, including its qualities and values associated with the night sky.

A star-filled night sky frames this dramatic view of rocky cliffs and gorge at Black Canyon of the Gunnison National Park, Colorado.
Night sky over Black Canyon of the Gunnison National Park.  G Owens / NPS

Reflections on the Night Skies as a Wilderness Value
Imagine you are in a wilderness area, whether it is a beach, mountain, or desert setting. Glaring light originating inside or outside wilderness may interrupt your opportunity to seek solitude. A visitor can explore deep into a wilderness area, yet still be followed by the glow of distant lights.

Light skyglow of LA at night from Mt. Whitney
Mt. Whitney, Sequoia National Park.

NPS/ Ben Banet

In the photo to the right, light pollution (skyglow), is clearly visible on the horizon from Mt. Whitney in Sequoia National Park. Even though the skyglow largely originates from southern California, over 200 miles distant, it has a profound effect on the park’s nighttime environment in designated wilderness.


Landres, Peter; Barns, Chris; Boutcher, Steve; Devine, Tim; Dratch, Peter; Lindholm, Adrienne; Merigliano, Linda; Roeper, Nancy; Simpson, Emily. 2015. Keeping it Wild 2: an Updated Inter-agency Strategy to Monitor Trends in Wilderness Character Across the National Wilderness Preservation System. Gen. Tech. Rep. RMRS-GTR-340. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 114 p

The Wilderness Act, Public Law 88-577 (16 U.S. C. 1131-1136), 88th Congress, Second Session, September 3, 1964

Last updated: July 10, 2024