PAD-US Data Overview

Science Center Objects

PAD-US is America’s official national inventory of U.S. terrestrial and marine protected areas (List of National Geospatial Data Assets) that are dedicated to the preservation of biological diversity and to other natural, recreation and cultural uses, managed for these purposes through legal or other effective means.

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Lands in PAD-US are mainly open space/resource lands owned in fee by agencies and non-profits. Conservation easements suitable for distribution in the public domain are also included. The current data set includes the “GAP Status Codes” of these lands, indicating how they are being managed for conservation purposes. A measure of public access for recreation is also included. PAD-US includes all Federal and most State lands, and many areas at regional and local scales, with plans underway to expand these holdings in the database.

Why are protected areas data important?

Detailed information about the conservation status of our country’s protected areas is crucial to improving our understanding of how well we are protecting the animals and plants that inhabit those areas. Natural resources decision-makers, planners, researchers, private interests and others also use this information in many other ways from locating and siting public resources such as recreation areas and energy facilities, to planning for and mitigating the impacts of climate change.

How GAP protected areas data can be used

Information about the conservation status of common species – a primary purpose of protected area analyses — is important for decision makers, planners, researchers, private interests, and others:

  • Biodiversity: Protected areas (parks, preserves, etc.) have often been set aside without full understanding of their value to species conservation. As a result, many protected areas have little significance in terms of biodiversity, while many biodiversity-rich areas lack protection. Information provided by the PAD-US can help land conservation decision makers better match biodiversity goals to land protection programs and activities.
  • Habitat Loss: Human population in the U.S. is predicted to grow by 25% in the next 50 years. This population increase, coupled with our land consumption patterns, means that there will be significant decreases in habitat for other species. Efforts to target the most effective lands for biodiversity conservation can offset some or many of the effects of habitat loss.
  • Climate: Accelerating climate change is elevating the importance of effectively targeted species protection efforts. For many species, warming climates could push them to the brink of extinction unless habitat migration corridors can be set aside. Protected Areas analysis is critical to understanding where to focus such corridor planning.
  • Energy Siting: Traditional and renewable energy projects such as oil, natural gas, solar and wind are planned and built across the U.S., often aided by governmental incentives. Protected area analysis can inform this planning and siting work, helping energy projects to find the best balance between habitat conservation and much-needed energy production.
  • Management: Agencies and non-profits that manage protected areas often lack good information about the full range of species that might be present or could be encouraged on their lands. The Gap Analysis Project can provide tools to improve land management practices that support continued biodiversity.
  • Public Access: There is increasing interest and research on the benefits of publicly accessible open space. In the current version of PAD-US, access is fully attributed but primarily assigned categorically instead of through individual unit review. However, this data can be used to view lands open for public recreation, incorporated into web or mobile based recreation apps, and utilized in other analyses on public access. As the PAD-US Team incorporates a more complete inventory of city and county data, it may also be useful for local or regional recreation and open space planning.  

Description of PAD-US data

How to cite data:

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, https://doi.org/10.5066/P955KPLE.

Main purpose:

The goals of the USGS Gap Analysis Project (GAP) are to provide landscape (e.g. State, watershed, regional and national) assessments of the conservation status of native vertebrate species and natural land cover types and to facilitate the application of this information to land management activities. The PAD-US geodatabase is required to organize and assess the status (i.e. land ownership and GAP Status Code) of protected areas for biodiversity protection. GAP has committed to develop and maintain PAD-US while implementing recommendations from the PAD-US Design Project (see A Map for the Future report) and expanding its scope to meet the needs of the recreation and public health communities (see Completing America's Inventory of Public Parks and Protected Areas report), to the extent resources allow. The PAD-US geodatabase is built to support landscape analyses by describing all protected areas to illustrate patterns and possible relationships with other factors (e.g. urban areas, migration corridors) across the landscape. Characteristics of protected areas such as land owner, name, location, size, public access, and a measure of biodiversity management intent are compiled and standardized.

Our current objective is to refine the PAD-US Data Manual to facilitate more efficient sharing of authoritative protected areas data between agencies and organizations that ultimately results in a comprehensive and accurate inventory of protected areas for the United States to meet a variety of needs (e.g. conservation, recreation, public health, transportation, energy siting, ecological, or watershed assessments and planning). In cooperation with UNEP-World Conservation Monitoring Centre (WCMC) and the Commission for Environmental Cooperation (CEC), GAP ensures PAD-US also supports continental and global decision making by maintaining World Database on Protected Areas (WDPA) Site Codes and International Union for the Conservation of Nature (IUCN) Categories for linkage to the North American Terrestrial Protected Areas Database and WDPA.

PAD-US data features:

PAD-US is available as a zipped national, DOI Region, or state geodatabase or shapefile. The following are included in PAD-US:

  • Geographic boundaries of public land ownership (primarily Federal and State, local government data is incorporated with increasing frequency) and voluntarily provided private conservation lands (e.g., Nature Conservancy Preserves or land trust easements) from authoritative data sources.
  • Standardized and original land owner, land manager, management designation and parcel name descriptions, areas and the source of geographic information of each mapped land unit.
  • GAP Status Code – conservation measure of each parcel based on protection level categories that provide a measure of management intent for the long-term protection of biodiversity.
  • IUCN category – a globally inter operable conservation measure required for a protected area’s inclusion into UNEP-World Conservation Monitoring Centre’s (WCMC) World Database on Protected Areas (WDPA).
  • Reference information – aggregator source and original GIS source and dates.
  • See “Supplemental_Info.txt” and metadata files included in download for more information.

How these data were aggregated:

Boundaries, and their descriptors, available in spatial databases (i.e. shapefiles or geodatabase feature classes) from land management agencies are the desired and primary data sources in PAD-US. If these authoritative sources are unavailable, or the agency recommends another source, data may be incorporated by other aggregators such as non-governmental organizations. Data sources are tracked for each record in the PAD-US geodatabase (see below).

'Aggregator Source' describes the Aggregator (Organization) credited with data aggregation, version of PAD-US when the update occurred, feature class the data reside in (unless mixed), reference to the original source data file, and a reference to describe the State location to manage boundary inconsistencies between agency datasets (from State data-steward submissions only). 'Aggregator Source' is attributed in the format 'organization name_PADUSversion+featureclass_filename.filetype' (e.g. TNC_PADUS1_4_SecuredAreas2008.shp). State aggregations also include a reference to the State in the format 'organization name_PADUSversion_filename.filetype_StateUSPS'. Aggregators may not always be able to define the geodatabase feature class as data may be mixed (e.g. MNDNR_PADUS2_0_MN2015_PADUS_MN_1.gdb_MN, NJOGIS_PADUS2_0Fee_OSPRI_August2017_NJ). Organization acronyms are used and underscore replaces spaces. A data aggregator submits data in the PAD-US format or includes nonprofit aggregators managing regional or national datasets with required fields for PAD-US translation. USGS is identified as aggregator when data translation is required (e.g. USGS_PADUS2_0Fee_BLM_SMA_ADMU_Union). Information about PAD-US Data Stewards and the Source Data they provide can be found at http://www.protectedlands.net/data-stewards/. This information will be made available on the USGS PAD-US web pages soon.

The 'GIS Source' field in the PAD-US geodatabase identifies the source of spatial data the aggregator obtained (e.g. WYGF_whmas08.shp) for each record. Files names match original source data provided by managing agencies to increase update efficiency and data transparency. This field is in a state of transition to fully meet standards as the original 'GIS Source' is not always provided in aggregated datasets.

The 'GIS Source Date' describes the date (yyyy/mm/dd) GIS data was obtained by the data source for aggregation. This date represents the best available data the GIS source has at the time.

Data limitations:

The Digital Object Identifier https://doi.org/10.5066/P955KPLE for PAD-US 2.0 provides the persistent reference that should be used to obtain the data for use. The U.S. Geological Survey and all contributing data partners shall not be held liable for improper or incorrect use of the data described and (or) contained herein. All information is created with a specific end use or uses in mind. This is especially true for GIS data, which is expensive to produce and must be directed to meet the immediate program needs. These data were created with the expectation that they would be used for other applications; however, inappropriate uses are listed in metadata. The list is in no way exhaustive but should serve as a guide to assess whether a proposed use can or cannot be supported by these data. For many uses, it is unlikely that PAD-US will provide the only data needed, and for uses with a regulatory outcome, authoritative agency data and field surveys should verify the result. PAD-US is recommended for users seeking basic information about more than one agency or organizations lands. Users should seek authoritative source data directly to answer questions regarding one agency or those requiring more frequent updates. Ultimately, it will be the responsibility of each data user to determine if these data can answer the question being asked. 

PAD-US additional data

Previous versions of PAD-US data include PAD-US Version 1-1, 1-2, 1-3, and 1.4. These are available in National, Regional, and State scales. Data are also available in  shapefile and geodatabase formats. Send a request to masoncroft@boisestate.edu with the data scale, format, and PAD-US version you need.

Contacts for PAD-US