Data Sources & Attribution
Every boundary drawn on an Elective Labs map comes from a government or government-mandated source. Some of those sources license their data under terms that require credit — we give it here, together with each source’s own licence language and a plain statement of what we change. Sources are added to this page in the same release that ships their data.
TIGER/Line and TIGERweb geographic boundaries
United States Census Bureau
- Licence:
- United States Government work — public domain (17 U.S.C. § 105)
- In the source’s words:
- Works of the United States Government are not subject to copyright protection.
- What we use:
- State, county, place, voting-district, and legislative boundaries nationwide — the precinct tier for every jurisdiction without a wired state source, and the county, place and legislative base everywhere.
- Changes we make:
- Geometry reprojected to WGS 84 and simplified for on-screen rendering; attributes reduced to identifiers and names.
Voting Precinct, Single Member District (2023), Ward (2022), and Advisory Neighborhood Commission (2023) boundaries
DC GIS / Open Data DC (Government of the District of Columbia)
- In the source’s words:
- voting-precinct [layer 0] "Voting Precinct" -> https://creativecommons.org/licenses/by/4.0
- What we use:
- District of Columbia voting precincts, ANC single-member districts, and wards.
- Changes we make:
- Geometry reprojected to WGS 84; ANC context outlines are derived by us by dissolving single-member districts on their ANC identifier.
WI Municipal Wards, County Supervisory Districts, Cities Towns & Villages (July 2026); Senate, Assembly & Congressional Districts
Wisconsin Legislative Technology Services Bureau (LTSB), publishing boundaries transmitted by county clerks under Wis. Stat. § 5.15(4)(br)
- Licence:
- Open public data (publisher’s statement)
- In the source’s words:
- “This is open and publicly available data. Use this data at your own risk. The LTSB is not”
- What we use:
- Wisconsin wards (the state’s precinct tier), county supervisory districts, municipal boundaries, and legislative districts.
- Changes we make:
- Geometry reprojected to WGS 84; aldermanic district outlines are derived by us by dissolving wards on their aldermanic identifier.
Election Precincts (2024) and legislative district boundaries
Hawaii Statewide GIS Program, Office of Planning and Sustainable Development, State of Hawaii
- Licence:
- No licence stated on the service — copyrightText names the publishers; no grant, no restriction
- In the source’s words:
- copyrightText: Hawaii State Office of Elections; Hawaii Statewide GIS Program
- What we use:
- Hawaii election precincts, congressional, state senate and house districts, and county council context outlines.
- Changes we make:
- Geometry reprojected to WGS 84; duplicate multi-part precinct rows deduplicated on the state’s precinct identifier.
Voting precinct boundaries ("Precincts" dataset)
Texas Legislative Council (data.capitol.texas.gov)
- In the source’s words:
- license_id: cc-by | license_title: Creative Commons Attribution | license_url: http://www.opendefinition.org/licenses/cc-by
- What we use:
- Texas county voting precincts, statewide.
- Changes we make:
- Geometry reprojected to WGS 84. Served live from the Texas Legislative Council’s REST layer (GISP.GIS.prec), whose rows match the CC-BY CKAN package; the REST service itself states no licence, so we rely on the package licence because the rows match (measured) — tx-phase1-2026-09-02.md leaves whether that reliance holds as an open question for counsel.
Precincts — Alaska voting precincts
Alaska Division of Elections (ArcGIS Online owner DOEALASKA)
- Licence:
- No licence stated on the item — captured as silence (licence-evidence/ak-election-geography.txt carries the first-captured date)
- In the source’s words:
- licenseInfo: (EMPTY — no licence stated on this item)
- What we use:
- Alaska voting precincts, statewide (402 rows).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier (which doubles as the label — the layer has no separate name field).
Election Districts — Delaware voting precincts
Delaware FirstMap (State of Delaware)
- Licence:
- Publisher’s stated terms (item licenseInfo)
- In the source’s words:
- “The State of Delaware makes no warranty or representation, expressed or implied, with respect to the quality, content, accuracy, completeness, currency, or non-infringement of proprietary rights, of any of the GIS or other data or information, or any other materials and items, that are displayed or made available for download from this site. All such data, information, items …
- What we use:
- Delaware voting precincts, statewide (531 rows).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier (which doubles as the label — the layer has no separate name field).
IowaPrecincts — Iowa voting precincts
Iowa Secretary of State, Iowa Legislatives Services Agency
- Licence:
- No licence stated on the item — captured as silence (licence-evidence/ia-precinct-boundaries.txt carries the first-captured date)
- In the source’s words:
- licenseInfo: (EMPTY — no licence stated on this item)
- What we use:
- Iowa voting precincts, statewide (1,660 rows).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier and name.
Idaho Voting Precincts — Idaho voting precincts
Idaho Secretary of State and Idaho Office of Information Technology Services GIS
- Licence:
- Publisher’s stated terms (item licenseInfo)
- In the source’s words:
- “Use Constraints: The Idaho Secretary of State (SOS) and the Idaho Office of Information Technology Services (ITS) maintain this data as a public service. Both SOS and ITS strive to ensure that all technical data and other information made available to the public is accurate, complete, and in conformance with the Idaho Public Records Act. Neither SOS nor the State of Idaho, …
- What we use:
- Idaho voting precincts, statewide (976 rows).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier and name.
Voting District Boundaries 2024 — Indiana voting precincts
Indiana Geographic Information Office (IndianaMap), crediting the Indiana General Assembly and Indiana Elections Division
- Licence:
- Publisher’s stated terms (item licenseInfo — a warranty disclaimer, not a licence: no restriction stated, no express grant)
- In the source’s words:
- “LIMITATION OF WARRANTIES AND LIABILITY - This product is provided "AS IS", without any other warranties or conditions, expressed or implied, including, but not limited to, warranties for product quality, or suitability to a particular purpose or use. The risk or liability resulting from the use of this product is assumed by the user. The Indiana Geographic …
- What we use:
- Indiana voting precincts, statewide (5,126 rows).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier and name.
Voting_Districts — Kansas voting precincts
Kansas Data Access and Support Center (DASC), Kansas GIS Policy Board
- In the source’s words:
- “The State of Kansas Geographic Information Systems Policy Board's Data Access and Support Center (DASC) and its representatives make no warranty or representation, either expressed or implied, with respect to the digital data and their documentation, their quality, performance, merchantability, or fitness for a particular purpose. The digital data are distributed on as-is …
- What we use:
- Kansas voting precincts, statewide (4,749 rows).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier and name.
SBE_Voting_Precinct_Boundaries — Kentucky voting precincts
Kentucky State Board of Elections
- Licence:
- Publisher’s stated terms (item licenseInfo)
- In the source’s words:
- “This geospatial data set depicting Kentucky Voting Districts (VTD) is compiled by the Kentucky State Board of Elections from precinct boundary files submitted by the respective County Board of Elections of each of Kentucky's 120 counties. The State Board of Elections performs a compiling and procedural review function only, as authorized under KRS 117.055 to 117.0557, and does …
- What we use:
- Kentucky voting precincts, statewide (3,193 rows).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier and name.
Wards and Precincts 2022 — Massachusetts voting precincts
MassGIS / Secretary of the Commonwealth of Massachusetts
- Licence:
- Publisher’s stated terms (item licenseInfo)
- In the source’s words:
- “This GIS web service is a public resource and may be used by anyone for their purposes. The data are public records and are based on the most up to date information at the time of publication. The information contained in this service is NOT to be construed or used as a "legal description." MassGIS, EOTSS and the Commonwealth of Massachusetts are not liable for …
- What we use:
- Massachusetts voting precincts, statewide (2,256 rows).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier (which doubles as the label — the layer has no separate name field).
2026_Voting_Precincts — Michigan voting precincts
State of Michigan (2026 Voting Precincts)
- Licence:
- Publisher’s stated terms (item licenseInfo)
- In the source’s words:
- “This dataset is a public record and, as more fully described below, there are no restrictions on the use, reproduction, or distribution of this dataset. Notwithstanding the foregoing, the public release of this dataset should not be construed, expressed or implied, as to whether any use constitutes a legally permissible purpose. It is the sole responsibility of the user to …
- What we use:
- Michigan voting precincts, statewide (3,895 rows).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier and name.
Bdry Votingdistricts — Minnesota voting precincts
Office of the Minnesota Secretary of State
- Licence:
- Publisher’s stated terms (item licenseInfo)
- In the source’s words:
- “Office of the Minnesota Secretary of State maintains this data as accurately as possible, but cannot assure 100% accuracy. For definitive precinct lines, please contact the jurisdiction (city, township, or county for unorganized territory) in question. To check precinct and districts or find polling place for an address, use the Secretary of State's Polling Place Finder: …
- What we use:
- Minnesota voting precincts, statewide (4,105 rows).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier and name.
Voting Precincts — Montana voting precincts
Montana State Library, Geographic Information Services
- Licence:
- Publisher’s stated terms (item licenseInfo)
- In the source’s words:
- “The Montana State Library Geographic Information Services provides this product/service for informational purposes only. The Library did not produce it for, nor is it suitable for legal, engineering, or surveying purposes. Consumers of this information should review or consult the primary data and information sources to ascertain the viability of the information for their …
- What we use:
- Montana voting precincts, statewide (728 rows).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier and name.
Govt_admin_election_district — New Jersey voting precincts
NJ Department of State, Division of Elections; published by NJ Office of GIS (NJOGIS)
- Licence:
- Publisher’s stated terms (item licenseInfo)
- In the source’s words:
- “The data are not survey data and must not be used as survey data. The geodetic accuracy and precision of the Geographic Information System (GIS) data has not been developed nor verified by a professional licensed land surveyor and shall not be nor is intended to be used in matters requiring delineation and location of true ground horizontal and/or vertical controls. See the …
- What we use:
- New Jersey voting precincts, statewide (6,348 rows).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier (which doubles as the label — the layer has no separate name field).
pct_2020 — Oklahoma voting precincts
Center for Spatial Analysis (University of Oklahoma) and Oklahoma State Election Board — the item's accessInformation reads 'Center for Spatial Analysis; Oklahoma State Election Board'
- Licence:
- Publisher’s stated terms (item licenseInfo)
- In the source’s words:
- “This Data is for Public use to be used as a spatial location tool.”
- What we use:
- Oklahoma voting precincts, statewide (1,984 rows).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier (which doubles as the label — the layer has no separate name field).
BND_Voting_Precincts_2022_spf — Rhode Island voting precincts
Rhode Island (RIGIS — Voting Precincts 2022)
- Licence:
- Publisher’s stated terms (item licenseInfo)
- In the source’s words:
- “This dataset is provided 'as is.’ The producer(s) of this dataset, contributors to this dataset, the Rhode Island Geographic Information System (RIGIS) consortium, the State of Rhode Island, and the University of Rhode Island do not make any warranties of any kind for this dataset and are not liable for any loss or damage however and whenever caused by any use of this dataset. …
- What we use:
- Rhode Island voting precincts, statewide (415 rows; one placeholder row excluded).
- Changes we make:
- Geometry reprojected to WGS 84; attributes reduced to the state’s precinct identifier (which doubles as the label — the layer has no separate name field).
National Agriculture Imagery Program (NAIP) orthoimagery
U.S. Department of Agriculture and U.S. Geological Survey — The National Map
- Licence:
- United States Government work — public domain (17 U.S.C. § 105)
- In the source’s words:
- USDA, USGS The National Map: Orthoimagery. Data refreshed June, 2024.
- What we use:
- The aerial photograph under the Watch Tower Orbital district view, loaded only for the jurisdiction being viewed.
- Changes we make:
- Exposure and saturation are adjusted on screen to match the real time of day over the district; a scrim is drawn over it so readouts stay legible. The imagery itself is not altered or redistributed.
Blue Marble and VIIRS Black Marble global imagery
NASA Global Imagery Browse Services (GIBS), Earth Science Data and Information System (ESDIS)
- Licence:
- United States Government work — public domain (17 U.S.C. § 105); NASA requests an acknowledgment
- In the source’s words:
- We acknowledge the use of imagery provided by services from NASA's Global Imagery Browse Services (GIBS), part of NASA's Earth Science Data and Information System (ESDIS).
- What we use:
- The planet seen from orbit at the start of the Watch Tower Orbital experience: the Blue Marble day surface and the VIIRS night-lights layer, blended by the real sun position.
- Changes we make:
- Brightness and the day/night blend follow the district’s local time. Tiles are displayed as served; nothing is redistributed.
OpenStreetMap street, building and land-use data via OpenFreeMap (OpenMapTiles schema)
© OpenStreetMap contributors · © OpenMapTiles · OpenFreeMap
- In the source’s words:
- OpenFreeMap © OpenMapTiles Data from OpenStreetMap
- What we use:
- Streets and their names, building footprints and heights, land use, parks and water for the district in view.
- Changes we make:
- Rendered in our own style; building footprints are clipped to the jurisdiction outline on the device. The map’s automatic attribution control is off, so this credit is carried on screen and here.
3DEP, SRTM and GMTED2010 terrain (Terrarium tiles, AWS Open Data mirror)
U.S. Geological Survey · Mapzen / Tilezen (tile build) · Amazon Web Services Open Data (hosting)
- In the source’s words:
- United States 3DEP (formerly NED) and global GMTED2010 and SRTM terrain data courtesy of the U.S. Geological Survey.
- What we use:
- Ground elevation for 3D terrain and hillshade under the district view.
- Changes we make:
- Vertical exaggeration of 1.15× for legibility. Tiles are displayed as served.
Open-Meteo current weather
Open-Meteo (open-meteo.com), on data from national weather services
- Licence:
- CC BY 4.0 — attribution required
- In the source’s words:
- Weather data by Open-Meteo.com
- What we use:
- Cloud cover over the district, read once every ten minutes through our own server, so the sky and the light on the Watch Tower Orbital map reflect the weather there now.
- Changes we make:
- Only a cloud fraction is used, to tint the sky, fog and exposure. No forecast is shown and nothing is redistributed.
We retain dated records of each source’s licence text as it read on the day we first relied on it, and we re-verify sources against their publishers on an ongoing basis. Questions about our data provenance: legal@electivelabs.org.