page_title: Cherry Springs State Park
section_title: Dark skies
hierarchical_section_title: Cherry Springs State Park / Recreation / Dark skies
caption_attribution_description: English: Trifid Nebula (M20), as seen from Cherry Springs State Park, Pennsylvania
context_page_description: Cherry Springs State Park is an 82-acre Pennsylvania state park in Potter County, Pennsylvania, United States. The park was created from land within the Susquehannock State Forest, and is on Pennsylvania Route 44 in West Branch Township. Cherry Springs, named for a large stand of Black Cherry trees in the park, is atop the dissected Allegheny Plateau at an elevation of 2,300 feet. It is popular with astronomers and stargazers for having "some of the darkest night skies on the east coast" of the United States, and was chosen by the Pennsylvania Department of Conservation and Natural Resources and its Bureau of Parks as one of "25 Must-See Pennsylvania State Parks".
  The earliest recorded inhabitants of the area were the Susquehannocks, followed by the Seneca nation, who hunted there. The first settlement within the park was a log tavern built in 1818 along a trail; the trail became a turnpike by 1834 and a hotel replaced the tavern in 1874, then burned in 1897. In the late 19th and early 20th centuries the old-growth forests were clearcut; the state forest was established in 1901 and contains second growth woodlands.
context_section_description: Astronomers and stargazers appreciate Cherry Springs State Park for the darkness and clarity of its skies, which make it "perhaps the last best refuge of the natural night sky" in the eastern half of the United States. The sky at Cherry Springs has been classified as a 2 on the Bortle Dark-Sky Scale, meaning it has almost no light pollution. Such "truly dark, starry skies are unavailable to two-thirds of the world's population, including 99 percent of people in the continental U.S. and Western Europe". With optimum conditions, 10,000 stars are visible with the naked eye at the park, clouds appear only as black holes in the starry sky, and the Milky Way is so bright that it casts a discernible shadow. In contrast, big city residents can see a few dozen stars at best, and even those in rural areas can typically only see 2,000–3,000 stars. The Milky Way cannot be seen by most in the eastern US, even when there is no moonlight to obscure it.
  The quality of the night skies at the park and its growing popularity for stargazing are the result of several factors. Cherry Springs is in the midst of the largely undeveloped 262,000-acre (106,000 ha) Susquehannock State Forest, and is on a summit 2,300 feet (701 m) above sea level. Because it is on the Allegheny Plateau, there are no mountain peaks to block the sky, and the Astronomy Field offers a 360 degree unobstructed view. The closest city is Williamsport, 60 miles (97 km) to the southeast. Surrounding communities sit in deep valleys, so the intervening terrain screens much of the light they produce; the park has no artificial skyglow in any direction. Cherry Springs is generally fog-free and its latitude puts it in excellent position to observe the Galactic Center of the Milky Way. The remote location also means there is little commercial air traffic to interfere with astrophotography, while PA Route 44 still offers relatively easy access to the park from Interstate 80.
  In addition to these natural factors, much has been done intentionally to make the skies at the park clear and dark and help keep them that way. Within the park, former overhead electrical lines have been buried so they do not obstruct views, all lighting is shielded, and all white lights have been converted to red, which has the least effect on night vision and astrophotography. Light from passing vehicles is blocked by earthen berms covered with grass, or shrubbery and spruce trees; the Astronomy Field gate has a special light-blocking tarp. The park's Dark Sky Fund has paid for many of these improvements since 1999.
  Since the 2006 acquisition of the Cherry Springs airport, a new Public Programming field has been established on the former airstrip. This field is northeast of PA Route 44 and is intended for educational programs or stargazing, but not for those who spend the night. Overnight observers and those with large telescopes use the Astronomy Field southwest of the highway. Nighttime visitors may only use flashlights with red filters, and may only point them at the ground. The Astronomy Field has further restrictions on lights, and parts of the park are light-free zones.
  To help preserve the dark skies at Cherry Springs State Park, Tri-County Rural Electric company installs light-shielding caps on outdoor lights at local homes for free. In 2001 the Pennsylvania General Assembly passed the "Outdoor Lighting Control Act", which both established the park as a "Dark Sky Preserve" and required minimal and shielded lighting at all new state facilities to reduce light pollution. A design guide for the Pennsylvania Wilds region, which includes the park, emphasizes the importance of maintaining dark skies. The DCNR spent $396,000 in June 2007 to buy mineral rights under 1,980 acres (800 ha) of the park and state forest to prevent natural gas drilling and associated development there.
  A wind farm has been proposed on a site 13.7 miles (22.0 km) from the park. In 2008 Potter County passed an ordinance that wind turbine lights shall not "interfere with the state-designated Dark Skies Preserve at Cherry Springs State
caption: The Trifid Nebula (M20) in Sagittarius, as seen from the park
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