Reference library
Maps & Navigation
9 guides, every one legally redistributable and traceable to its source.
FAA Digital VFR Raster Charts
Sectionals double as excellent large-area emergency planning maps (terrain, obstacles, airports as evacuation/medevac points). Public domain, zero cost, and popular with the prepper audience.
Federal Aviation Administration, Aeronautical Information Services · ~20-60 MB per sectional zip; full US sectional set a few GB
FEMA National Flood Hazard Layer
Flood zones, base flood elevations, and floodways for pre-disaster planning — 'is my home/route in a flood zone' is a headline offline feature for a survival app, and flooding is the most common US disaster.
FEMA · National GDB ~12 GB uncompressed; county extracts typically 10-500 MB
GNIS Domestic Names
Millions of named natural features (springs, gaps, peaks, valleys) with coordinates — the backbone of offline place-name search/geocoding so users can find 'Cold Spring' with no connectivity. Springs and water features are survival-critical search targets.
USGS / US Board on Geographic Names · National names file on the order of ~100-300 MB uncompressed
HIFLD Open — Hurricane Evacuation Routes
The only national compilation of designated hurricane evacuation routes — an obvious offline layer for coastal subscribers.
DHS Homeland Infrastructure Foundation-Level Data (HIFLD) · Small (tens of MB)
National Park Service park maps
The iconic, professionally designed park brochure maps every visitor recognizes, plus authoritative trail/boundary GIS for the exact places subscribers will be when lost. NPS confirms government-produced maps may be reproduced, modified, and redistributed without restriction.
US National Park Service · ~1-30 MB per park map PDF; full set a few GB
NOAA Electronic Navigational Charts
Full US coastal/Great Lakes/intracoastal coverage — depths, hazards, anchorages — valuable for coastal-evacuation and boating-survival scenarios, and remarkably small to bundle.
NOAA Office of Coast Survey · Complete 'All ENCs' package ~794 MB
USFS FSTopo
Often fresher and more trail-accurate than US Topo inside national forests (the Forest Service's own primary base map series, with FS road numbers critical for rescue callouts). National forests are where a large share of survival scenarios actually happen.
USDA Forest Service · ~10-30 MB per quad; covers all 193 million acres of NFS land
USGS Historical Topographic Map Collection via topoView
1884-2006 scans at 1:24k-1:250k. Older quads often show springs, cabins, mine shafts, and trails dropped from modern maps — genuinely useful survival detail — and make a differentiating 'historic layer'.
U.S. Geological Survey (NGMDB) · 178,000+ maps; ~10-50 MB each depending on format
USGS US Topo Quadrangle Maps
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.
U.S. Geological Survey (USGS) · ~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