This Insight accompanies the Congressional District Geography Workbook, a Microsoft Excel file that congressional users can download from CRS.gov. The workbook provides information about U.S. House districts as configured in the 119th Congress (2025-2026).
It supersedes the version published for the 118th Congress: CRS Insight IN12393, Congressional District Geography Workbook (118th Congress): An Interactive Tool for Congressional Users, by Ben Leubsdorf.
This new workbook incorporates updated datasets, new categories of geographic areas and features, and revised district boundaries in five states (Alabama, Georgia, Louisiana, New York, and North Carolina).
The Congressional District Geography Workbook contains information about selected geographic areas and features located inside each of the 435 congressional districts across all 50 states. It also includes information for the District of Columbia, Puerto Rico, American Samoa, Guam, the Northern Mariana Islands, and the U.S. Virgin Islands.
It contains 46 categories of geographic areas and features, including the following:
A geographic area or feature is associated with a specific congressional district when it is located fully or partly inside that district's boundaries. An area or feature may be located entirely within a single district or split between two or more districts.
Thirteen categories do not include any locations in the five U.S. territories: bikeshare systems, border crossings, colonias, Federal Reserve banks, food assistance, major sports venues, museums, national laboratories, Native American areas, private schools, spaceports, train stations, and tribal governments. Other categories may provide limited coverage of locations in the territories.
The workbook, when downloaded and opened in Microsoft Excel, contains five sheets that can be accessed via tabs at the bottom of the screen:
The workbook sheets are formatted for ease of use and password-protected to prevent changes.
CRS can provide Members and staffers with additional analysis and information upon request (e.g., points of interest not included in the workbook, directory-type contact information for selected categories, or the extent of overlaps for areas split among more than one district).
CRS acquired data from the sources described below in June 2026, unless otherwise noted. These datasets were the most recent available, though they may have been compiled or updated at different times. When direct crosswalks to 119th Congress districts were not available, CRS generally used the tigris and sf packages in the R statistical programming language to match longitude and latitude coordinates, as provided by agencies or geocoded by CRS, with corresponding congressional districts. Not all categories may be comprehensive. The workbook may contain errors, including potential mistakes present in the source datasets.
The Administrative Office of the U.S. Courts provided coordinates for federal courthouses via the Department of Homeland Security (DHS) Homeland Infrastructure Foundation-Level Data (HIFLD) Secure repository. The Federal Courthouse category includes resident courthouses, nonresident courthouses, temporary locations, and temporarily vacated facilities but excludes other judicial branch offices and U.S. Tax Court facilities. Because courthouses are represented by point locations, congressional district assignments may not capture their full physical footprints. For example, the courthouse building that straddles the border between Texarkana, AR, and Texarkana, TX, is assigned to the 1st Congressional District of Texas (TX-01) but not the 4th Congressional District of Arkansas (AR-04).
The U.S. Army Corps of Engineers at the U.S. Department of Defense (DOD) provided coordinates for ports, dams (via the National Inventory of Dams), and levees (via the National Levee Database). (DOD is "using a secondary Department of War designation" under Executive Order 14347, dated September 5, 2025.) The Port category includes ports on rivers and lakes as well as seaports and port statistical areas, which are defined in legislation and may extend well beyond the ports' physical infrastructure. The Dam list is limited to dams designated as having high hazard potential, meaning the loss of at least one life is probable from a dam failure. Each dam's name is accompanied by information about the dam's primary purpose, if available. Additional information is available in CRS Report R45981, Dam Safety Overview and the Federal Role, by Anna E. Normand, and information about other dam locations is available in the National Inventory of Dams. Levee locations are based on points and lines representing system elements but do not include areas protected from flooding by levees. The Levee category may not include all flood control structures and systems.
The Bureau of Indian Affairs in the U.S. Department of the Interior (DOI) provided coordinates for tribal government offices via its Tribal Leaders Directory. This category contains headquarters locations for American Indian and Alaska Native entities recognized by the federal government. Because these offices are represented by point locations, their district assignments may not capture the full extent of their authority. The separate Native American Area category includes reservations and other tribal areas. Additional information is available in CRS Report IR10001, Tribal and Other Indigenous Lands in the 119th Congress, by Mariel J. Murray and Mainon A. Schwartz.
The Bureau of Transportation Statistics at the U.S. Department of Transportation provided coordinates for airports, bikeshare systems, coastal and inland commercial waterways, ferry terminals, spaceports, train stations, and transit systems (based on transit agency office and stop locations). The Airport list is limited to public use airports eligible for federal funding as listed in the Federal Aviation Administration's (FAA's) National Plan of Integrated Airport Systems. The Bikeshare System list is based on active docking station locations and does not include operators of dockless scooters or bikes. The Commercial Waterway category is a subset of the Navigable Waterway Network that includes bays, canals, channels, estuaries, Great Lakes links, harbors, intracoastal waterways, lakes, and rivers but excludes sealanes and open water routes as well as waterways that are not normally used for freight. The Spaceport list includes commercial and federal space launch and reentry sites. The Train Station list includes Brightline stations in Florida, with those coordinates provided by the Palm Beach Metropolitan Planning Organization. The Transit System category assigns an agency to any congressional district that contains the agency's office or at least one bus, subway, or other stop served by that agency. Because facilities and shipping lanes are represented by points and lines, their district assignments may not capture the full extent of their physical footprints.
The Census Bureau in the U.S. Department of Commerce provided information about counties, county subdivisions, Native American areas, places, and school districts via its Congressional District Relationship Files, which contain crosswalks between 119th Congress districts and geographic areas used in the 2020 census. For Connecticut, the County category includes both historical counties and modern planning regions. The Native American Area category includes federal and state reservations, off-reservation trust lands, Hawaiian Home Lands, Alaska Native Village Statistical Areas, Oklahoma Tribal Statistical Areas, State Designated Tribal Statistical Areas, and Tribal Designated Statistical Areas.
CRS matched state legislative districts in the 50 states, the District of Columbia, and Puerto Rico to congressional districts using the Census Bureau's 2024 State Legislative Block Equivalency Files (BEFs) and 119th Congress BEFs. Relationships between state legislative and congressional districts were established based on shared census blocks, with split blocks assigned to all potentially matching districts.
Customs and Border Protection (CBP) at DHS provided coordinates for Office of Field Operations facilities at land, ferry, and rail border crossings with Canada and Mexico via the HIFLD Secure repository, supplemented by information on crossings between Texas and Mexico from the Texas Department of Transportation. CRS excluded CBP facilities more than 10 miles away from the border as well as administrative offices, other ports of entry such as airports and seaports, and several border crossings known to be permanently closed.
The Defense Department's Defense Installations Spatial Data Infrastructure program provided coordinates for military installations, including ranges and training areas, as of FY2024. The source dataset excludes some facilities due to national security concerns as well as relatively small facilities, including many National Guard and Reserve sites. It also excludes U.S. Coast Guard facilities, which fall under DHS.
The Energy Information Administration at the U.S. Department of Energy (DOE) provided coordinates for power plants. The preliminary dataset for 2025, the most recent information available, contains all grid-connected, electricity-producing power plants in the 50 states, the District of Columbia, and Puerto Rico with nameplate capacity of at least 1 megawatt.
The Environmental Protection Agency (EPA) provided coordinates for charitable food assistance organizations via its Excess Food Opportunities Map, municipal solid waste landfills via its Landfill Methane Outreach Program database, and federal Superfund sites via its Superfund National Priorities List (NPL) Where You Live Map. The nonprofit organizations Feeding America and Hunger Free America provided data to EPA on food bank, food pantry, and soup kitchen locations. This list is probably not comprehensive. Users can consult local community contacts for further information about area organizations. Information about federal programs that support such organizations is available in CRS Report R45408, The Emergency Food Assistance Program (TEFAP): Background and Funding, by Kara Clifford Billings, and CRS Report R48124, Connecting Charitable Food Assistance Organizations to Federal Funding Information and Resources, by Sarah K. Braun and Alyse N. Minter. Roughly 12% of landfills in the dataset could not be matched with any district due to missing coordinates and are omitted. Each landfill's name is accompanied by information about its current status: open, closed, or unknown. The list of Superfund sites comprises all locations currently on the EPA's NPL, excluding proposed and deleted sites.
The Federal Reserve provided addresses for Federal Reserve banks and branch locations, which CRS geocoded to produce longitude and latitude coordinates. Each branch name is accompanied by the name of its parent bank—for example, Detroit Branch (Federal Reserve Bank of Chicago).
The U.S. Forest Service in the U.S. Department of Agriculture (USDA) provided information about national forests and other National Forest System units in each district as part of the agency's Land Areas of the National Forest System report for FY2025. The National Forest System includes national forests, national grasslands, land utilization projects, purchase units, research and experimental areas, and other areas. Additional information is available in CRS Report R43872, National Forest System Management: Overview and Issues for Congress, by Anne A. Riddle.
The U.S. Geological Survey (USGS) at DOI provided coordinates for state and territorial capitol buildings as part of its National Map, which also includes the U.S. Capitol. The District of Columbia's Department of Energy and Environment provided coordinates for the equivalent John A. Wilson Building. USGS also provided coordinates for 161 volcanoes in a 2018 report that assessed potential threats. See CRS In Focus IF11987, The National Volcano Early Warning and Monitoring System, by Linda R. Rowan for more information. A volcano's point location may not capture the full extent of its physical footprint. For example, the Yellowstone Caldera "supervolcano" is assigned only to Wyoming's at-large congressional district (WY-AL) even though the site extends into Idaho's 2nd Congressional District (ID-02) and Montana's 1st Congressional District (MT-01). For additional information on volcanoes in Alaska, see CRS Report R48529, Alaska's Active Volcanoes: Federal Role in Research, Monitoring, and Warning, by Linda R. Rowan. For additional information on volcanoes in Hawaii, see CRS Report R48622, Hawaii's Active Volcanoes: Federal Role in Research, Monitoring, and Warning, by Linda R. Rowan.
The Government Publishing Office provided information about federal depository libraries in each congressional district via the Federal Depository Library Directory.
The U.S. Department of Health and Human Services provided coordinates for Head Start service locations. Some locations may appear multiple times if they offer more than one program at the same address (e.g., an Early Head Start program and a Head Start Preschool program hosted in the same building). Additional information is available in CRS In Focus IF11008, Head Start: Overview and Current Issues, by Karen E. Lynch.
DHS provided coordinates for emergency operations centers via the Federal Emergency Management Agency for facilities operated by state and territorial governments and via an archived HIFLD Open dataset from 2025 for facilities operated by local governments such as cities, counties, and tribes.
The U.S. Department of Housing and Urban Development (HUD) provided crosswalks between congressional districts and five-digit ZIP codes via its HUD USPS ZIP Code Crosswalk Files. This should not be taken as a definitive placement of ZIP codes in congressional districts, as slight differences in methodology may produce different results. HUD also provided coordinates for colonias, communities near the U.S.-Mexico border that meet criteria such as "lack of potable water supply, lack of adequate sewage systems, and lack of decent, safe, and sanitary housing" (42 U.S.C. §1479(f)(8)). Because colonias are represented by point locations, congressional district assignments may not capture their full physical footprints. In addition, HUD provided coordinates for public and assisted housing, including public housing developments; multifamily buildings subsidized by HUD through programs such as Section 8 Project Based Assistance, Section 202 Supportive Housing for the Elderly, and Section 811 Supportive Housing for Persons with Disabilities; multifamily buildings subsidized by USDA in rural areas; and residential properties subsidized through the Low-Income Housing Tax Credit program. The Public and Assisted Housing category does not include private buildings that accept Section 8 Housing Choice Vouchers. Roughly 3% of buildings could not be matched with congressional districts due to invalid or missing coordinates and are omitted. Each development or building name is accompanied by information about the total number of units in that building or development, if available, and the general type of assistance provided there. Some buildings may appear more than once if they receive multiple forms of assistance. Some properties may be partially assisted, so the total number of units shown may not match the number of units considered to be receiving federal assistance. Additional information is available in CRS Report RL34591, Overview of Federal Housing Assistance Programs and Policy, by Maggie McCarty, Libby Perl, and Katie Jones.
The Institute of Museum and Library Services provided information about and coordinates for public libraries (from FY2024) and museums (from 2018). Each library's name is accompanied by its system name, unless the two names are identical. The Museum category includes related institutions such as arboretums, art galleries, historical societies, and zoos.
The Internal Revenue Service's Exempt Organizations Business Master File Extract contained mailing address information for chambers of commerce (tax-exempt 501(c)6 organizations with classification code 3) registered with the U.S. Department of the Treasury. CRS geocoded addresses to generate longitude and latitude coordinates, then matched each point with a corresponding congressional district.
The Mine Safety and Health Administration at the U.S. Department of Labor provided coordinates for active and intermittently active coal, metal, and nonmetal mines via its Mine Data Retrieval System. Each mine's name is accompanied by information about its primary commodity. Because mines are represented by point locations, a congressional district assignment may not capture the full extent of a mine's physical footprint.
The National Center for Education Statistics at the U.S. Department of Education provided information about public schools (elementary and secondary), private schools (elementary and secondary), and postsecondary institutions (such as colleges and universities) via its Education Demographic and Geographic Estimates program. The most recent files available were 2023-2024 data for private schools and 2024-2025 data for public schools and postsecondary institutions. Because schools are represented by point locations, a congressional district assignment may not capture the full extent of a campus. In addition, the Postsecondary Institution category may include administrative offices that are not necessarily associated with student populations.
The National Park Service in DOI provided information about national parks and other National Park System units in each district. Additional information is available in CRS Report R41816, National Park System: What Do the Different Park Titles Signify?, by Laura B. Comay.
The Pacific Northwest National Laboratory provided coordinates for existing data centers via its IM3 Open Source Data Center Atlas. This list is likely incomplete, as there is no authoritative public inventory of data centers in the United States. It may also be out of date, because construction of new facilities is ongoing. Information about additional data center locations is available from some private sector data aggregators. Congressional offices may contact CRS for assistance with locating and accessing those datasets.
The U.S. Department of Veterans Affairs (VA) provided coordinates for VA facilities via its VA Facilities API. These include but are not limited to Veterans Benefits Administration regional offices, national cemeteries, state and tribal cemeteries, soldiers lots, VA medical centers, community-based outpatient clinics, vet centers, and mobile vet centers.
The Major Sports Venue category includes U.S. arenas and stadiums used by professional baseball (MLB and MiLB), basketball (NBA, WNBA, and G League), football (NFL and UFL), hockey (NHL, PWHL, AHL, and ECHL), and soccer (MLS and NWSL) teams, as well as additional stadiums with seating capacity of 30,000 or more. The FAA provided coordinates for stadiums, MLB provided coordinates for minor league ballparks, and CRS assembled and geocoded addresses for smaller stadiums and enclosed arenas in May 2026.
The National Laboratory category comprises offices and other facilities described on the individual websites of the 17 national laboratories overseen by DOE. These include 10 laboratories under the DOE Office of Science and three national security laboratories under the National Nuclear Security Administration. Additional information is available in CRS In Focus IF12692, Department of Energy (DOE) Office of Science, by Todd Kuiken, and CRS Report R48194, The U.S. Nuclear Security Enterprise: Background and Possible Issues for Congress, by Anya L. Fink. CRS assembled and geocoded addresses for each facility. Because each facility is represented by a point location, its district assignment may not capture the full extent of its physical footprint.
This workbook was initially published in January 2025.
CRS plans to publish a new version of the Congressional District Geography Workbook in early 2027 to incorporate changes to congressional district boundaries for the 120th Congress (2027-2028).