Choose a place to start. Everything here comes from official map data stored on the phone.
National parks, wilderness areas and state parks. Download one before you lose signal. It is stored on this phone and works with no connection.
A ring on the meter fills as you go, and the spot where you reach it is marked on your map.
Your own landmark: kept on this phone, shown on your map and in your journal.
Night stops are mapped campsites near the even split. Permits and where camping is allowed are not in the data: check with the park.
Send it to someone who will call 911 if they don't hear from you. TrailTruth reminds you here when you're due back; it never contacts anyone for you.
Pick what the next hiker should know. It goes on the map where you stand, with today's date. No names, no free text.
Call 911
No signal? Try a text to 911. If you are lost but safe, stay where you are.
TrailTruth answers only from official park, trail, water and elevation data stored on your phone. It tells you when it does not know.
It does not know: today's closures, weather, flash-flood risk, whether a spring has water, trail conditions, snow, or how hard a trail is for you.
Do not use it as your only navigation. Carry a paper map and compass, tell someone your plan, and check the park's alerts before you go.
Map data: USGS National Map (trails from the National Park Service), USGS GNIS names, USGS 3DEP elevation, USGS NHD water, and community-mapped paths and points © OpenStreetMap contributors (ODbL), via Overture Maps.
Your AI trail companion. A small AI that talks with you about each answer in its own voice. It runs inside this phone's browser on Google's open Gemma model, so nothing leaves the phone and it costs nothing. A checker reads every fact it says against the map data: it fixes what it gets wrong or leaves it out. It needs a large one-time download (about 580 MB) and a recent phone.
Model license. The companion is Google's Gemma 3 1B, fine-tuned by Neverclosed. It is provided under the Gemma Terms of Use and is subject to the Gemma Prohibited Use Policy. Notice. Neverclosed modified the model files (fine-tuned them), and they carry a notice saying so. You may not use the trail companion for anything the Gemma Prohibited Use Policy forbids, or against the law: see the terms.
Using TrailTruth means you agree to the terms (no copying, sharing or taking apart the app, its data or its model) and the privacy policy. The app counts, per day, how often your personal link opens it and is used in a park: numbers only, no locations.
To use TrailTruth, tap I agree to accept the terms and the privacy policy.You agreed to the terms and the privacy policy.
Four quick questions. All are optional. We keep only your answers and the date: no name, no location, no device ID.
Your answers are tied to your link, not your name. See privacy for what we keep.