Darkest States in the US 2025
State | # of IDA Certified Sites | IDA-Certified Sites | |
|---|---|---|---|
 | Arizona | 9 | Chiricahua NM, Flagstaff Area NM, Grand Canyon NP, Kartchner Caverns SP, Oracle SP, Petrified Forest NP, Pipe Spring NM, Tonto Monument NM, Tumacacori NP |
 | Arkansas | 1 | Buffalo National River NR |
 | California | 3 | Anza-Borrego Desert SP, Death Valley NP Joshua Tree NP |
 | Colorado | 7 | Dinosaur NM, Florissant Fossil Beds NM, Great Sand Dunes NP, Jackson Lake SP, Kelso Dunes NP, Mesa Verde NP, Slumgullion Center CP, |
 | Connecticut | 3 | Beckley Furnace SP, Campbell Falls SP, Dennis Hill SP |
 | Florida | 2 | Big Cypress Preserve NP, Kissimmee Prairie SP |
 | Georgia | 1 | Stephen C. Foster SP |
 | Idaho | 2 | Craters of the Moon NM, Central Idaho Dark Sky NR |
 | Illinois | 1 | Middle Fork River SF |
 | Maine | 1 | Katahdin Woods & Waters NM |
 | Michigan | 2 | Dr. T.K. Lawless CP, Headlands SP |
 | Minnesota | 2 | Boundary Waters Canoe NWR, Voyageurs NP |
 | Montana | 1 | Medicine Rocks SP |
 | Nevada | 2 | Great Basin NP Massacre Rim WSA |
 | New Mexico | 8 | Capulin Volcano NM, Chaco Culture NP, Clayton Lake SP, Cosmic Campground, El Morro NM, Fort Union NM, Salinas Pueblo Missions NM, Valle de Oro NWR |
 | North Carolina | 2 | Mayland Earth to Sky SP Pisgah SP |
 | Ohio | 1 | Geauga SP |
 | Oregon | 1 | Prineville Reservoir SP |
 | Pennsylvania | 1 | Cherry Springs SP |
 | Tennessee | 2 | Obed Wild & Scenic River NR Pickett CCC Memorial SP |
 | Texas | 7 | Big Bend NP, Big Bend Ranch SP, Copper Breaks SP, Devil's River SNA, Enchanted Rock SNA, South Llano River SP, UBarU Camp & Retreat |
 | Utah | 19 | Antelope Island SP, Arches NP, Bryce Canyon NP, Canyonlands NP, Capitol Reef NP, Cedar Breaks NM, Dead Horse Point SP, East Canyon SP, Fremont Indian SP, Goblin Valley SP, Goosenecks SP, Hovenweep NM, Jordanelle SP, Kodachrome Basin SP, Natural Bridges NM, North Fork SP, Rainbow Bridge NM, Steinaker SP, Timpangogos NM, |
 | Virginia | 5 | James River SP, Natural Bridge SP, Rappahannock CP, Sky Meadow SP, Staunton River SP |
 | Washington | 1 | Rockport SP |
 | Wisconsin | 1 | Newport SP |
- The Bortle scale is a method of measuring the darkness of the night sky for a particular location, with Class 9 possessing the most light pollution and Class 1 possessing the lowest light pollution (and therefore optimal viewing)
- The IDA column indicates if a site is certified by the International DArk Sky Association. A Bortle scale value is given for each site where it is known.
- IDA listings utilize the following abbreviations: NP = national park | SP = state park | NF = national forest | SF = state forest | NWR = national wildlife reserve | SRA = state recreational area
- Local astronomy clubs are a recommended source for precise, local-scale guidance in locating the darkest (and most ideal) viewing locations.
The Bortle scale serves as a valuable tool for measuring the darkness of the night sky, providing insight into optimal stargazing locations across the United States. Ranging from Class 1 (minimal light pollution) to Class 9 (severe light pollution), the scale offers astronomers and enthusiasts a standardized method for assessing the quality of celestial observation sites.
States such as Alaska, California, and Oregon boast some of the darkest skies in the country, with Bortle scale ratings ranging from 7 to 13. These regions offer unparalleled opportunities for stargazing, with designated sites like Anza-Borrego Desert State Park, Death Valley National Park, and Prineville Reservoir State Park providing pristine views of the cosmos.
Furthermore, the International Dark-Sky Association (IDA) plays a crucial role in preserving and promoting dark-sky sites worldwide. Certified locations, including national parks, state forests, and wildlife reserves, offer protected environments for observing the wonders of the night sky.
Local astronomy clubs serve as invaluable resources for enthusiasts seeking precise, local-scale guidance in locating the darkest and most ideal viewing locations. By collaborating with these organizations and utilizing resources such as the IDA’s Dark Sky Finder, individuals can embark on unforgettable journeys to explore the beauty of the cosmos from some of the darkest states in the nation.
