USGS US Topo Quadrangle Maps
U.S. Geological Survey (USGS)
The canonical US backcountry map. 1:24,000 topo quads with contours, water, trails, and structures — exactly what a survival app's offline map library should anchor on. USGS explicitly confirms bulk redistribution and commercial reuse (see usgs.gov/faqs/are-usgs-topographic-maps-copyrighted and the bulk-order FAQ); The National Map Downloader exports a CSV product list for scripted bulk fetches of state-size areas.
Editor's notes
Retain copyright notices on 2010-2016 quads (commercial road data). USGS asks for source acknowledgment ('Map courtesy of the U.S. Geological Survey'). Do not imply USGS endorsement. Quads are refreshed on a ~3-year cycle; check publication dates.
GeoPDF (layered, georeferenced; bulk delivery is GeoPDF-only), also GeoTIFF/KMZ for many quads via topoView
~15-60 MB per 7.5-minute quad; ~1,000-1,500 quads per state (roughly 30-75 GB/state); full current CONUS set is in the low terabytes
This work is available at no charge from its publisher at the link above. Members get our cleaned, searchable offline edition, plain-text version, and update tracking.
Source & license
US federal government work (public domain), with three narrow copyright exceptions: commercially licensed road data on 2010-2016 quads, Alaska orthoimagery, and pre-2017 Hawaii orthoimagery — those quads are still freely redistributable if the copyright notice in the map collar/metadata is retained.
Use of this material does not imply endorsement by its publisher or any government agency.