Lightscape / Night Sky

NPS Management Policies 2006 direct the service to preserve, to the greatest extent possible, the natural lightscapes of parks, which are natural resources and values that exist in the absence of human-caused light. Natural lightscapes are not found at the park due to surrounding development and roadways that cross the park. Lightscape conditions at Valley Forge NHP are typical of suburban communities near major cities.

There are two primary sources of light pollution from beyond the park boundary. Land to the northeast, east, and southeast of the park is highly developed and emanates a constant glow, visible from many vantage points in the park. Although dark-sky fixtures and more strategic usage of night lighting could reduce the magnitude of light somewhat, the large number and variety of usages would make it difficult to reduce by a great degree. The Valley Forge rest stop on the turnpike is located immediately south of the park, and this point-source is the single intrusion in an otherwise dark sky to the south. Its lighted commercial signs and parking lot lights are fully visible even on gray afternoons, and are highly visible from Outer Line Drive and Wayne Statue, which is positioned on one of the highest vantage points in the park.

On the north side of the park, views southward toward the Schuylkill River are dark, while views to the north encompass low levels of residential lighting. The river corridor itself is one of the darkest areas of the park - depending on one’s vantage point, the only visible light is from vehicles on PA Route 23 and the US 422 bridge. Views west from the park are relatively dark, with only occasional point-sources of residential or vehicle lights visible.

Within the park, artificial light point-sources also contribute to light pollution. Various structures and monuments are illuminated each night throughout the year, including the Washington Memorial Chapel, Visitor Center, and the National Memorial Arch. A few parking lots are dimly lit for part of each evening, including the lower Visitor Center lot, Ranger Station lot, Maintenance lot, and Betzwood lots. One street lamp is located near the covered bridge.