Skip to main content
U.S. flag

An official website of the United States government

Protected Areas Database of the United States (PAD-US) 2.1 - World Database on Protected Areas (WDPA) Submission (ver 1.1, April 2021)

March 29, 2021

The United States Geological Survey (USGS) - Science Analytics and Synthesis (SAS) - Gap Analysis Project (GAP) manages the Protected Areas Database of the United States (PAD-US), an Arc10x geodatabase, that includes a full inventory of areas dedicated to the preservation of biological diversity and to other natural, recreation, historic, and cultural uses, managed for these purposes through legal or other effective means. The PAD-US is developed in partnership with many organizations, including coordination groups at the [U.S.] Federal level, lead organizations for each State, and a number of national and other non-governmental organizations whose work is closely related to the PAD-US. Learn more about the USGS PAD-US partners program. The United Nations Environmental Program - World Conservation Monitoring Centre (UNEP-WCMC) tracks global progress toward biodiversity protection targets enacted by the Convention on Biological Diversity (CBD) through the World Database on Protected Areas (WDPA) and World Database on Other Effective Area-based Conservation Measures (WD-OECM) available at: See the Aichi Target 11 dashboard (…) for official protection statistics recognized globally and developed for the CBD, or here for more information and statistics on the United States of America's protected areas: It is important to note statistics published by the National Oceanic and Atmospheric Administration (NOAA) Marine Protected Areas (MPA) Center and the USGS GAP differ from statistics published by the UNEP-WCMC as methods to remove overlapping designations differ slightly and U.S. Territories are reported separately by the UNEP-WCMC (e.g. The largest MPA, "Pacific Remote Islands Marine Monument" is attributed to the United States Minor Outlying Islands statistics). At the time of PAD-US 2.1 publication (USGS-GAP, 2020), NOAA reported 26% of U.S. marine waters (including the Great Lakes) as protected in an MPA that meets the International Union for Conservation of Nature (IUCN) definition of biodiversity protection. USGS-GAP expects to publish PAD-US 2.1 Statistics and Reports in the spring of 2021. In 2007, the USGS-GAP began collaborating with the UNEP-WCMC and the IUCN protected areas experts to submit data for the WDPA following PAD-US updates (See attached "VersHist-WDPA.txt" for more information). As a requirement to fulfill the USGS's mission to assess management intent for the long-term protection of biological diversity, PAD-US includes a nationally relevant conservation measure, the GAP Status Code, and the globally recognized IUCN Category measure. These conservation measures are assigned to each designated management area and many overlap (e.g. Wilderness Area, National Forest). The UNEP-WCMC and the IUCN suggest GAP Status Code 1 and 2 protected areas from PAD-US for inclusion in the WDPA as these areas, primarily managed for the long-term protection of biodiversity, meet the definition of protection defined by IUCN (UNEP-WCMC, 2019; UNEP-WCMC, 2016; Coad et al., 2010). The NOAA manages the MPA Inventory and assigns IUCN Categories to MPAs before sharing data with the USGS for inclusion in the PAD-US. NOAA is the authoritative source of MPAs data and summary statistics for the U.S. available at: The USGS, the NOAA, and other agencies and nonprofits collaborate to review and refine conservation measure assignments to ensure terrestrial and marine protected areas in PAD-US, sent to the UNEP-WCMC for inclusion in the WDPA, reflect the best available spatial representation of the U.S. protection network primarily managed for biodiversity. Research to support OECM ( submissions from the PAD-US (or other sources) to the UNEP-WCMC for the WD-OECM is pending. In summary, the relationship between the USGS, the NOAA, and the UNEP-WCMC is as follows: USGS manages and publishes the full inventory of U.S. marine and terrestrial protected areas data in the PAD-US representing diverse values, developed in collaboration with many partners in the U.S. and; USGS is the primary source of U.S. marine and terrestrial protected areas data for the WDPA, developed from a subset of the PAD-US in collaboration with the NOAA, other agencies and non-governmental organizations in the U.S., and the UNEP-WCMC and; UNEP-WCMC is the authoritative source of global protected area statistics from the WDPA and WD-OECM and; NOAA is the authoritative source of MPA data in the PAD-US and MPA statistics in the U.S. and; USGS is the authoritative source of PAD-US statistics (including areas primarily managed for biodiversity, multiple uses, and public access). The PAD-US 2.1 Combined Marine, Fee, Designation, Easement feature class (GAP Status Code 1 and 2 only) is the source of protected areas data in this WDPA update (See attached "PADUS_2_1_WDPASchemaMetadata.xml" for more information). Tribal areas and military lands represented in the PAD-US Proclamation feature class as GAP Status Code 4 (no known mandate for biodiversity protection) are not included as spatial data to represent internal protected areas are not available at this time. The USGS submitted more than 43,000 protected areas from PAD-US 2.1, including all 50 U.S. States and Territories, to the UNEP-WCMC for inclusion in the May 2021 WDPA, available at The IUCN protected areas in the U.S. are managed by thousands of agencies and organizations across the country and include sites such as National Parks, National Wildlife Refuges, National Monuments, Wilderness Areas, State Parks, State Wildlife Management Areas, Local Nature Preserves, City Natural Areas, The Nature Conservancy and other Land Trust Preserves, and Conservation Easements. The boundaries of these protected places (some overlap) are represented as polygons in the PAD-US, along with informative descriptions such as Unit Name, Manager Name, and Designation Type. As the WDPA is a global dataset, their data standards (UNEP-WCMC, 2019) require simplification to reduce the number of records included, focusing on the protected area site name and management authority (See attached "PADUS_2_1_WDPASchemaMetadata.xml" for more information). The NOAA is the sole source of all MPAs in PAD-US and the National Conservation Easement Database (NCED) is the source of conservation easements. The USGS aggregates authoritative federal lands data directly from managing agencies for PAD-US, while a network of State data-stewards provide state, local government lands, and some land trust preserves. National and other non-governmental organizations contribute spatial data directly for PAD-US. The USGS translates the biodiversity focused subset of PAD-US into the WDPA schema (UNEP-WCMC, 2019) for efficient aggregation by the UNEP-WCMC. The USGS assigns WDPA Site Identifiers, a persistent identifier for each protected area, provided by the UNEP-WCMC. Given the numerous organizations involved, sites may be added or removed from the WDPA between PAD-US updates. These differences may reflect actual change in protected area status; however, they also reflect the dynamic nature of spatial data or Geographic Information Systems (GIS). Many agencies and non-governmental organizations are working to improve the accuracy of protected area boundaries, the consistency of attributes, and inventory completeness between PAD-US updates. In addition, USGS continually seeks partners to review and refine the assignment of conservation measures in PAD-US. Note that Waterfowl Production Area (WPA) Easements in PAD-US 2.1 overestimate biodiversity protection (see PAD-US 2.1 Easement feature class where Agg_Src = 'FWS_PADUS2_1Easement_FWSInterest_Simplified' AND Loc_Ds = 'WPA') and are not included in the WDPA 2.1 Submission. The spatial data represents the overall tract boundary containing the wetland easement (about 12.5 million acres primarily in North Dakota and South Dakota) rather than the wetland area protected via easement (an estimated 13% of total parcel area based on documented acres provided by the U.S. Fish and Wildlife Service (FWS)). In consultation with the FWS, the USGS omitted WPA Easements from the WDPA 2.1 submission and will revise their classification in PAD-US 3.0 from GAP Status Code 2 to GAP Status Code 4 to reflect spatial data gaps. They will not be included in the WDPA 3.0 Submission. Please contact the USFWS Cadastral Data Working Group at with any questions regarding WPA Easements. Version History First posted - 2009 (Version 1.0 - available from the PAD-US: Team Revised - 2010 (Version 1.1 - available from the PAD-US Team: No WDPA Revision - 2011 (Version 1.2) Revised - 2013 (Version 1.3 - available from the PAD-US Team: Revised - April 2016 (Version 1.4 - Revised - April 2020 (Version 2.0 - Revised - March 2021 (Version 2.1 - Contacts The PAD-US version 2.1 - World Database on Protected Areas (WDPA) Submission will be available in the May 2021 version of the WDPA and summarized in the Protected Planet 2021 Digital Report (, published by UNEP-WCMC. Go to to view or download WDPA data. Contact the PAD-US Team ( or U.S. Focal Point for the WDPA ( for more information. References Coad, Lauren; Burgess, Neil; Loucks, Colby; Fish, Lucy; Scharlemann, Jorn; Duarte, Lisa; Besançon, Charles. (2010). Reply to Jenkins and Joppa - Expansion of the global terrestrial protected area system. BIOLOGICAL CONSERVATION. 143. 5-6 ST. UNEP-WCMC (2019). User Manual for the World Database on Protected Areas and world database on other effective area-based conservation measures: 1.6. UNEP-WCMC: Cambridge, UK. Available at: UNEP-WCMC (2016). Protected areas data for the United States. UNEP-WCMC. Cambridge, UK. Available at:… U.S. Geological Survey (USGS) Gap Analysis Project (GAP), 2020, Protected Areas Database of the United States (PAD-US) 2.1: U.S. Geological Survey data release, U.S. Geological Survey (USGS), Gap Analysis Project (GAP), March 2020, Protected Areas Database of the United States (PAD-US), Version 2.0 Combined Feature Class - World Database on Protected Areas (WDPA) Submission, U.S. Geological Survey (USGS) Gap Analysis Project (GAP), 2018, Protected Areas Database of the United States (PAD-US): U.S. Geological Survey data release,

Publication Year 2021
Title Protected Areas Database of the United States (PAD-US) 2.1 - World Database on Protected Areas (WDPA) Submission (ver 1.1, April 2021)
DOI 10.5066/P9IVLRSS
Authors United States Geological Survey
Product Type Data Release
Record Source USGS Digital Object Identifier Catalog
USGS Organization Science Analytics and Synthesis Program