Offline maps. Live data. Anywhere.
Deadzone is three services that share one set of federal data. The iOS app puts offline topographic maps and on-demand intelligence in your pocket. The web portal builds the trip before you leave. The SMS service brings the same intelligence back over Iridium, T-Satellite, or a one-bar cell pocket. All three pull from NWS, NOAA, USGS, USFS, and more than twenty other government sources. None of them make anything up.
One app. The whole backcountry stack.
Offline topography, fourteen federal overlay layers, on-device terrain tools, and an AI that reads live federal data — all in the same pocket computer. Pick a system to see it.
Three services sharing one set of federal data.
Every claim is tied to a live source — never to model memory. Intelligence and live data, orchestrated by AI from twenty-two federal feeds — the same answers on a desktop, on a trail, and from a satellite.
Offline maps + accessible intelligence.
Topographic detail and overlay layers downloaded before you leave — fully offline. And whenever you have any link at all (Wi-Fi, cell, camp Starlink), ask anything: AI orchestrates live federal data into a sourced answer. Tap any feature on the map to start.
Build the trip before you leave.
Drop waypoints on a desktop map. Get a pre-trip briefing written from live conditions. Saved locations and trips sync to the iOS app before you go.
Text the same AI from offgrid.
Send a question over Iridium (Garmin inReach), Starlink (T-Satellite), or a one-bar cell pocket. The AI stays the same. The reply comes back as plain SMS.
Four ways to reach Deadzone.
When you can't browse — but you can text — Deadzone still answers. Same intelligence, same federal sources, four ways in.
(Garmin inReach)
True backcountry, offshore, deep canyons — anywhere with line of sight to sky. The channel to bet your life on.
A Garmin inReach or other Iridium-enabled device with two-way messaging active.
(T-Satellite)
Anywhere with open sky, no extra device. Standard SMS extended over satellite — your phone behaves the same as it would in coverage.
A supported iPhone or Android device on T-Mobile's T-Satellite plan.
(one-bar pockets)
Weak-signal pockets — your phone can send SMS but can't browse. Common in canyons, treelines, and the rim of a coverage hole.
Any phone with carrier SMS service. No special device, no special plan.
Camp Wi-Fi, town, Starlink at base, the airport before you fly — full chat with every data source wired in.
The Deadzone iOS app or web portal, and any data connection.
Apple Satellite (Globalstar) — not a channel we recommend. The opportunistic satellite negotiation has been unreliable in our testing. If the link happens to land, the SMS goes through — but treat it as a best-effort backup, not a path you can plan around.
Pick what fits the trip.
Every paid tier gets the full map experience. Tiers differ on chat, signals, and briefings — the things that actually cost us to run.
- Offline maps + overlays
- 25 chats/mo
- 25 SMS signals/mo
- 1 briefing/mo
- Custom AI context
- Offline maps + overlays
- 75 chats/mo
- 75 SMS signals/mo
- 2 briefings/mo
- Custom AI context
- Offline maps + overlays
- 250 chats/mo
- 250 SMS signals/mo
- 15 briefings/mo
- Custom AI context
Out of signals?
Top up your SMS quota without upgrading. Packs expire at the end of the month.
Honest answers to the questions you'd ask.
Does Deadzone work without a Garmin?
Yes. The iOS app's offline maps, trip planning, briefings, and in-app chat all work without any satellite device.
A Garmin inReach (or other Iridium device) is the most reliable channel from anywhere on Earth — true backcountry, offshore, deep canyons. T-Satellite (T-Mobile's Starlink direct-to-cell plan) covers the same anywhere-with-open-sky use case without a separate device. For weaker situations, a one-bar cell pocket is enough for plain SMS to land. The iOS app handles everything else.
Which phones can text Deadzone over satellite?
T-Satellite (Starlink direct-to-cell) is the phone-satellite path we recommend. T-Mobile's plan extends standard SMS over Starlink to supported iPhone and Android devices, anywhere with open sky. The behavior is identical to sending an SMS in a regular coverage zone — the bytes just take a different path.
iPhone Apple Satellite (Globalstar) we do not promote. The opportunistic satellite negotiation has been unreliable in our testing — Globalstar coverage and handset link acquisition are inconsistent enough that we can't recommend it as a real channel. If you have it and the link happens to land, the SMS will go through, but treat it as a best-effort backup, not a primary path.
How is this different from Gaia, OnX, or CalTopo?
They're map apps — good ones. Deadzone is the next generation of the category: the map, plus the intelligence layer they don't have. Live conditions, closures, regulations, and terrain answers — orchestrated by AI from twenty-two federal feeds, tied to sources, never to model memory. Tap any feature and start a real conversation about it. Get a briefing written for the specific weekend you're going.
The tools go further, too: viewshed and sun-and-shade modeling computed on-device from terrain data — analysis that normally means a separate desktop tool — and a dispersed-camping layer scored from 1-meter lidar that exists nowhere else. And when you leave coverage entirely, the same intelligence answers by satellite SMS. If you only need a map, those are great products. This is what comes after.
What about Android?
The web portal works on any modern browser, Android included. A native Android app is on the roadmap but not in this early-access release — we wanted to ship one platform that's actually good before splitting our attention.
Do I need a subscription to use the map?
Every paid tier — Trail, Expedition, and Pro — includes the full offline map experience: all overlays, unlimited regions, saved locations, the works. We don't gate the map.
What scales with the tier is the AI-driven services: in-app chats, offgrid SMS signals, and pre-trip briefings. Those are the things that cost us to run, so those are where the tier differences live.
What data sources does Deadzone use?
NWS for weather, NOAA for marine and tides, USGS for water and elevation, USFS for trails and roads, BLM for routes, NPS for alerts and recreation, EPA AirNow for air quality, FAA AWC for aviation weather, NRCS for snowpack, NDBC for buoys, InciWeb and the federal wildfire feeds for fire perimeters, CMS for hospital data, Recreation.gov, OpenStreetMap, and more.
We cache aggressively and query only when you ask — so the data is fresh when it matters and cheap when it doesn't.
What happens when I hit a monthly limit?
For SMS signals, you can buy a top-up pack (Scout or Ranger) without upgrading. For in-app chats and briefings, you'll need to upgrade to the next tier — we're transparent about that because those are our most expensive services and a top-up model would muddy the pricing.
All limits reset the first of the month.