Gap Analysis Project


How well are we protecting common plants and animals? Gap Analysis is the science of answering this question. Developing the data and tools to support that science is the mission of the Gap Analysis Project (GAP). Check out our SCIENCE section on the left to begin exploring GAP.

Species Data

Species Data

GAP has delineated species range and predicted distribution maps for more than 2,000 species that occur within the continental U.S. as well as Alaska, Hawaii, and Puerto Rico. 

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Land Cover Data

Land Cover Data

The GAP/LANDFIRE National Terrestrial Ecosystems data set includes detailed vegetation and land cover patterns for the continental United States. The data set incorporates the Ecological System classification system developed by NatureServe.

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Protected Areas Data

Protected Areas Data

PAD-US is America’s official national inventory of U.S. terrestrial and marine protected areas (List of National Geospatial Data Assets).

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Date published: March 6, 2019

New Species Habitat Distribution Maps Now Support Conservation Planning at a National Scale

A new dataset of habitat distribution for terrestrial vertebrate species in the conterminous United States is now available from the USGS.

Date published: September 14, 2018

National species data for CONUS are now available


The largest data release in the 20+ year Gap Analysis effort in the number of data layers and extent. Over 1,700 species/subspecies known range and predicted habitat maps for terrestrial vertebrates covering the conterminous United States.

Date published: July 18, 2018

New Federal Recreation Map

Data from PAD-US has enabled the development of a new map highlighting federal recreation lands and waters in the U.S. 


Year Published: 2017

Integrating multiple data sources in species distribution modeling: A framework for data fusion

The last decade has seen a dramatic increase in the use of species distribution models (SDMs) to characterize patterns of species’ occurrence and abundance. Efforts to parameterize SDMs often create a tension between the quality and quantity of data available to fit models. Estimation methods that integrate both standardized and non-standardized...

Pacifici, Krishna; Reich, Brian J.; Miller, David A.W.; Gardner, Beth; Stauffer, Glenn E.; Singh, Susheela; McKerrow, Alexa; Collazo, Jaime A.
Pacifici, K., Reich, B. J., Miller, D. A. W., Gardner, B., Stauffer, G., Singh, S., McKerrow, A. and Collazo, J. A. (2017), Integrating multiple data sources in species distribution modeling: a framework for data fusion*. Ecology, 98: 840–850.

Year Published: 2017

Long-term fish monitoring in large rivers: Utility of “benchmarking” across basins

In business, benchmarking is a widely used practice of comparing your own business processes to those of other comparable companies and incorporating identified best practices to improve performance. Biologists and resource managers designing and conducting monitoring programs for fish in large river systems tend to focus on single river basins or...

Ward, David L.; Casper, Andrew F.; Counihan, Timothy D.; Bayer, Jennifer M.; Waite, Ian R.; Kosovich, John J.; Chapman, Colin; Irwin, Elise R.; Sauer, Jennifer S.; Ickes, Brian; McKerrow, Alexa
Ward, D.L., Casper, A.F., Counihan, T.D., Bayer, J.M., Waite, I.R., Kosovich, J.J., Chapman, C.G., Irwin, E.R., Sauer, J.S., Iches, B.S., and McKerrow, A.J., 2017,Long-Term Fish Monitoring in Large Rivers: Utility of “Benchmarking” across Basins: Fisheries, no. 42, v. 2, p

Year Published: 2016

A comparison of NLCD 2011 and LANDFIRE EVT 2010: Regional and national summaries.

In order to provide the land cover user community a summary of the similarity and differences between the 2011 National Land Cover Dataset (NLCD) and the Landscape Fire and Resource Management Planning Tools Program Existing Vegetation 2010 Data (LANDFIRE EVT), the two datasets were compared at a national (conterminous U.S.) and regional (Eastern...

McKerrow, Alexa; Dewitz, Jon; Long, Donald G.; Nelson, Kurtis; Connot, Joel A.; Smith, Jim
McKerrow, A., J. Dewitz, and D. Long. 2016. A Comparison of NLCD 2011 and LANDFIRE EVT 2010: Regional and National Summaries.