What Is a Natural Resource Condition Assessment?

Natural Resource Condition Assessments (NRCAs) are cooperative projects with the National Park Service (NPS) that set out to evaluate and report current conditions, identify critical data gaps, and summarize threats and stressors for a subset of priority natural resources at a specific park unit. The selected resources are typically natural resources or features that are unique to a park or that represent an integral component of ecosystems/landscapes in the park. To complete these assessments, existing scientific data and information from a variety of NPS and non-NPS sources are synthesized and summarized, and an overall condition is assigned to each priority resource. NRCAs are intended to represent a synthesis of existing data and literature for the key resources of a given park, which assists natural resource planning activities and provides background information for future park resource staff.

For more background information, such as program guidance and current program status, visit the NPS NRCA website

An Example Framework for a NRCA we completed for Shilo National Military Park. Click image to enlarge.

How We Create NRCA Reports

Collaboration is key

At the beginning of each NRCA, GSS staff visit the park to meet with park personnel and resource specialists in order to identify the priority resources that are important to the park. These discussions result in the creation of a project “framework” that contains multiple components (key park resources that will receive individual assessments in the NRCA document). Once a set of resource components is finalized, measures (metrics), threats and stressors, and reference conditions are identified for each.

A reference condition serves as a baseline for comparison of current condition; this may be a specific point in time, an ecological threshold, or an established mandated standard. GSS works with NPS staff to obtain as much relevant information as possible (e.g., literature, spreadsheets, spatial data), and to fully understand all necessary aspects of each component, such as data interpretations and limitations. Each component section authored by GSS is reviewed by NPS staff and/or outside topical experts before inclusion in the final report.

NRCA Report Highlights

Glacier Bay National Park & Preserve

Glacier Bay National Park and Preserve is located in Southeast Alaska and was established in 1925. Together, the park and preserve protect a total area of over 3.3 million acres of terrestrial and aquatic habitats. In addition to the many tidewater glaciers in the park, Glacier Bay also supports a tremendous diversity of terrestrial and aquatic resources. Glacier Bay represents a unique scientific area in North America, as the region is experiencing rapid deglaciation. This deglaciation has allowed scientists to observe ecological succession as it unfolds, and has also allowed researchers to investigate how these changes affect all of the plants and animals that interact with these unique ecosystems.

In total, 24 components were selected for the park’s NRCA, and current conditions were generally found to be good. Selected components included several terrestrial and aquatic wildlife communities and species. Examples of components in Glacier Bay’s NRCA include: moose, bears (brown and black), mountain goats, breeding birds, many marine mammals (e.g., humpback whales, Steller sea lions, sea otters), and several groups of fish species (e.g., salmon, Pacific halibut). Priority components were not isolated to wildlife species, however, as condition assessments were also completed for glaciers, marine shorelines, wilderness character, air and water quality, and underwater soundscape. Despite being well isolated and protected under NPS regulations, the park resources are still at risk, as global climate change, anthropogenic pollutants, and park visitation all threaten the health of resources in the park.

Carlsbad Caverns National Park

Carlsbad Caverns in southern New Mexico was first protected in 1923 as a national monument. It became a national park in 1930 and was designated as a UN World Heritage Site in 1995. The park contains 120 caves, many of which support bat colonies and other unique cave fauna. The geological features of these caves are impressive; Lechuguilla Cave, for example, contains rare and unique speleothems, some of which are not known to occur in any other caves worldwide.


Above ground, Carlsbad Caverns protects a diverse desert ecosystem, with plants ranging from evergreen trees to desert grasses and cacti. Seeps and springs provide critical water sources for wildlife in this arid environment and were included as a central component in the NRCA. Other components included birds, herpetofauna, bats, dark night skies, and human impacts on caves. The region around Carlsbad Caverns has recently become a hotbed for oil and gas industry development, which poses a threat to many of the park’s resources, from wildlife to air quality and the groundwater that feeds the park’s springs.

Chickamauga & Chattanooga National Military Park

This military park, which contains units in both Tennessee and Georgia, commemorates the Civil War battles of Chickamauga (won by the Confederates) and Chattanooga (won by the Union) during the fall of 1863. It is considered the oldest and largest military park in the country, established in August of 1890. Its many disjunct units came under NPS management in 1933. Although “Chick-Chatt” is primarily known for its historical and cultural significance, the park supports a wide variety of natural resources, including some rare and unique features.

Open grassy areas called “limestone cedar glades” are interspersed within the hardwood forests of the Chickamauga Battlefield Unit. The shallow soils and high sunlight levels in the glades support many endemic (found only in this area and ecosystem type) plant species. The hardwood forests of Chick-Chatt also contain small, temporary wetlands that provide valuable habitat for breeding amphibians and their young. The location of the park so near the urban area of Chattanooga has offered many management challenges, particularly at Lookout Mountain and Moccasin Bend, where the park is bordered by housing and other development.