Natural Resource Monitoring at George Washington Memorial Parkway

Marsh elevation monitoring at Dyke Marsh National Wildlife Preserve.

NPS

The National Capital Region Inventory & Monitoring Network monitors air quality, amphibians, birds, forest pests, vegetation, invasive plants, stream water, and stream fish and macroinvertebrates at George Washington Memorial Parkway. The results of that monitoring provide park managers with scientific information for decision-making.

George Washington Memorial Parkway is a scenic parkway that preserves the Potomac River Gorge and shoreline while serving as a memorial to the first President of the United States. The Potomac Gorge featuring steep cliffs and rich eastern deciduous forests is home to many rare species and natural communities.

The park’s main natural resource management concerns are invasive plants and diseases, overpopulation of deer, and encroaching urban development. Stormwater management is a big concern for stream ecosystems. Regional air quality and land use patterns can have strong effects on park resources.

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GWMP Natural Resource Information

Resource Briefs: Air & Climate, Amphibians, Forest Birds, Forest Vegetation, Stream Biota (Fish & Macroinvertebrates), Water, Marsh Elevation, and Other Vital Signs 

Reports: Air & Climate, Amphibians, Forest Birds, Forest Vegetation, Geology & Fossils, Small Mammals, Soil Data, Stream Biota (Fish & Macroinvertebrates), Water Quality, Natural Resource Condition Assessment for GW Memorial Parkway

Explore and Visualize Data:
Search GWMP Species Lists
Dive into water data with an Interactive Water Visualizer
Unpack ecological Data Packages

NCRN Monitoring at GW Memorial Parkway: By the Numbers

*Site numbers as of 2026. These can change over time.
NPS staff may refer to our Online Map for sampling site locations.

What We Monitor	Sites at GW Memorial Parkway*	Monitoring Frequency	Information We Collect
Amphibians	69 known wetland pools	Annual sampling on a subset of known wetlands Wetland sites are monitored twice per sampling period	Species occupancy and richness for salamanders, frogs, and toads in vernal pools
Birds – forest only	20 forest bird sites	Forest plots are monitored twice a year	Forest bird species and abundance Bird habitat quality
Forest vegetation	20 forest vegetation sites	Approximately a quarter of plots each year on a four-year cycle	Deer browse Fallen and standing woody debris Targeted diseases and pests Targeted invasive plant species Trees, shrubs, vines, and specific non-woody plants
Stream biota – fish and macroinvertebrates	At streams listed below	Periodic sampling 2007-2014, 2019-2023	Aquatic macroinvertebrates taxa and abundance Fish species and abundance Stream physical habitat including bank stability, stream shading, and distance from developed areas
Stream water quality	4 stream sites. Mine Run, Pimmit Run, Turkey Run, and Minnehaha Creek on Maryland side of Potomac River. (Spout Run to be added in 2027.)	Stream sites are monitored every other month	Acid neutralizing capacity Dissolved oxygen pH Salinity/specific conductance Stream width, depth, flow, and discharge Total nitrogen and phosphorus Water temperature
Marsh elevation	12 sites in Dyke Marsh	Marsh elevation sites are monitored once a year	Marsh surface elevation