New here? Start at rangertrak.com — what it is, and how to try it without a GitHub account. Try the app itself at rangertrak.org; its built-in Help is the full reference. This repo is the source, issues and releases.
RangerTrak tracks and maps CERT, ACS, SAR, wildland-fire and other teams who are reachable only by HAM radio. Field teams radio in their locations; a scribe at the command post transcribes them; RangerTrak builds a single mapped log of who was where, when, and in what condition — for live situational awareness and after-action documentation.
It is a Progressive Web App that runs entirely in the browser. No server, no account, and no Internet required once it has been loaded — which is the point, because the command post often has none. No API key is required either, for RangerTrak's core function; address lookup uses a keyless default (OpenStreetMap's Nominatim), with an optional Google Geocoding key if you supply your own.
Because reading latitude and longitude over a radio is slow and error-prone, locations can also be reported as Plus Codes (computed on-device, always available) or street addresses (a live lookup against Nominatim/Google — see FIELD-GUIDE.md, needs Internet).
Try it: https://RangerTrak.org
| Document | For | Contents |
|---|---|---|
| In-app Help | Operators, ECs, scribes | The source of truth for every screen — built into the app, always matches the version you're running, and works with no Internet |
| rangertrak.com | Everyone | The front door: what RangerTrak is, the Field Notes blog, and a short field guide that points into Help |
| FIELD-GUIDE.md | Operators, ECs, scribes | The printable pre-mission companion: preparing a device so it still works when the network doesn't |
| ARCHITECTURE.md | Developers | How the app is built: map engines, geocoding, bundle and loading strategy |
| DEVELOPING.md | Developers | Running, testing, releasing, updating dependencies, deploying |
| contributing.md | Everyone | Code of conduct |
| CHANGELOG.md | Everyone | Release history |
| .vscode/SETUP.md | Developers | VS Code workspace setup |
New to RangerTrak? Start at rangertrak.com, then the in-app Help. Before a real mission, print or read the Field Guide's "Before the mission" — the difference between a prepared device and an unprepared one is the difference between a working tool and a blank screen.
- Works offline. Entering reports, the roster, the Radio Log, coordinate conversion and mission backups all stay on the device and need no connection.
- Locations however the field reads them out: lat/long in three notations, MGRS, UTM, Maidenhead and Plus Codes, all converted on-device. Street addresses work too, but need Internet.
- Two map engines on one page: Leaflet over online road and topo maps, with areas saveable for offline use, and MapLibre + PMTiles with a bundled offline basemap. Each ranger gets a distinct marker and a trail.
- ICS paperwork: a printable ICS-309 comms log, and ICS-213 messages generated from radio log entries (field reports).
- Roster, statuses, mission and operational period, all configurable per mission.
- Backup, export and demo data: spreadsheets, whole-mission backups (optionally passphrase-encrypted), and demo scenarios for training.
- Free and open source, under the AGPL.
How to use each screen is in the app's Help, not here; developer detail is in ARCHITECTURE.md.
⚠️ The roster contains personal information — names, addresses, phone numbers, and call signs that map to public licence records — stored unencrypted on the device, unless you turn on device encryption (Mission → Data safety). Mission backups can also be encrypted with a passphrase (optional, and blank still writes a plain file). See Help → Your data in the app for handling guidance.
What has actually shipped is in CHANGELOG.md and the
releases — that is the accurate record,
and it moves most weeks. The issues page is
the place for comments and feature suggestions, and
milestones group the longer-range ones;
neither is a complete picture of day-to-day work. A consolidated public ROADMAP.md will
follow once the next release's scope is firm.
Note on version numbers: the minor version bumps rapidly and deliberately. 0.x.0 means
"a meaningful batch of work landed," not "this is stable and supported." The release others
are actively encouraged to adopt will be 1.0.0-rc.1, and it is not near.
Known gaps worth stating plainly:
- It will not interrupt you. Overdue teams are shaded green through red on the map, the roster and the Radio Log, against your mission's own check-in interval — but nothing beeps or pops up, and the times refresh when a screen redraws rather than ticking.
- There is no geo-fence — nothing warns that a ranger is outside an expected area.
- The bundled offline map covers the whole world at low detail, with street-level detail
only in a demo's area while that demo is loaded. Your own area needs saving on the street map beforehand, or a
.pmtilesfile loading for it. - What3Words is not wired up, and would be the only coordinate format needing a key and a network call — every other one is computed on-device.
- The UI is English-only and the ICS forms are the US versions.
Using it: visit https://RangerTrak.org, then name the mission on the Mission page, add people on the Rangers page, and enter reports on Field Entry (the RangerTrak link at top left). Help → Start here walks through it.
Developing it:
git clone https://github.com/SteadyEOC/RangerTrak.git
cd RangerTrak
npm install
npm startDetails, testing and release process in DEVELOPING.md.
RangerTrak is a free, open-source project from SteadyEOC - see rangertrak.com. We'd love to hear how you use RangerTrak and what you need from it.
- GitHub issues — bugs and specific pieces of work.
- GitHub discussions — open-ended conversation about the project.
- Pull requests — including small edits made entirely in GitHub's browser editor; no local setup needed for a documentation fix.
- Email — RangerTrak@steadyeoc.com.
- Support — RangerTrak is free and stays free. If it helps your team, you can buy the developer a coffee. That goes to John Cornelison personally, not a charity, so it isn't tax-deductible.
Copyright © 2019–2026 John Cornelison
RangerTrak is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. See LICENSE for the full text.
- Using RangerTrak — including at your EOC, exercise, or incident — is completely free and always will be. The AGPL places no obligations at all on people who simply use the application.
- If you modify RangerTrak and distribute it, or run your modified version as a network service, you must make your modified source available under the same license.
- Contributions are welcome. Note that the project may offer commercially licensed versions in future, so contributors may be asked to sign a Contributor License Agreement.
(Releases prior to this change were published under the MIT License and remain available under those terms.)
"(We) all agreed that this is a WOW program with high value added to SAR. I really hope you continue to refine it!"
— Michael Meyer, KB7MTM, Vashon ACS