Data Sources & Licensing
Open Map Lab is built on open science, public domain federal repositories, and collaborative geospatial datasets. We honor and cite our primary data suppliers.
US Census Bureau (cartographic boundaries via us-atlas, and TIGERweb)
States/counties: 2017 edition; ZCTAs and places: current TIGERweb releaseState and county outlines come from the Census cartographic boundary files (2017 edition, redistributed as TopoJSON by us-atlas and generalized to about 1:10,000,000). ZIP Code Tabulation Areas and city/place polygons are queried live from Census TIGERweb.
Copernicus GLO-90 Digital Elevation Model
Served by the Open-Meteo elevation API (Terrarium tiles as fallback)European Space Agency worldwide Digital Elevation Model (DEM) derived from TanDEM-X radar satellite interferometry, providing ~90m global land surface heights.
OpenFreeMap & OpenStreetMap Contributors
Continuous Community Updates 2026Global community cartography vector tiles rendered via OpenFreeMap liberty style. Map data is copyright OpenStreetMap contributors.
IANA Time Zone Database (`tzdata`)
Current release shipped with your browser (ICU)Historical and current civil time zone boundary specifications and Daylight Saving Time rules managed by Paul Eggert and the IANA community.
timezone-boundary-builder (via tz-lookup)
tz-lookup 6.1Time zone polygons derived from OpenStreetMap, packaged and simplified by the tz-lookup library. Used to find which IANA zone contains a coordinate; accuracy is roughly a kilometre near zone borders.
Natural Earth
world-atlas 2.0 (Natural Earth 1:50m)Public domain map dataset. Country boundaries use the 1:50m scale, redistributed as TopoJSON by world-atlas 2.