Sustainable Outdoor Lighting Principles - Night Skies (U.S. National Park Service)

Driftless Region county wants to become an international dark sky park

Support for management actions to protect night sky quality: Insights from visitors to state and national park units in the U.S. - ScienceDirect

Night Skies (U.S. National Park Service)

Good heavens: How light pollution is threatening our sky

Managing Lightscapes - Night Skies (U.S. National Park Service)

Preserving Our Night Skies - Xanterra Travel Collection®

Strong Visitor Support for Steps to Limit Light Pollution (U.S. National Park Service)

Dark-sky preserve - Wikipedia

MultiBrief: 10 US dark-sky parks worth a visit