How to import a GPX file into CalTopo

The short answer

Open or create a map in CalTopo, use its import option to upload the .gpx file, and the track appears as a line object on that map alongside anything else you have drawn or added. On an iPhone with the CalTopo app installed, sharing a .gpx file to it from Files or from the recording app works the same way any other share-sheet import does.

Where the GPX file comes from in the first place

CalTopo only has a track to show once some other app hands it one as a file — it is not itself a GPS recorder in the way a phone-based tracking app is. Most recording apps write the points they logged, latitude, longitude, elevation and a timestamp for each, into a single .gpx file through an export or share action. TrailCam exports a single route or a whole history this way, in GPX 1.1, which is the version CalTopo and the rest of the mapping world expect.

Getting it into CalTopo

From a computer, into an open map

CalTopo is primarily a browser tool, and a map you have open there has an import option that accepts a GPX file uploaded from your desktop. The track comes in as a line object on that specific map, not into some general library — if the destination is a map you have not created yet, make that first.

From an iPhone, through the share sheet

If the CalTopo app is on the phone, a .gpx file found in Files, in an email, or from the export action of the app that recorded it can be shared straight to CalTopo the way it can be shared to any app that registers itself for that file type. This adds the track to a map the same way the web import does.

Other formats CalTopo accepts

GPX is not the only thing CalTopo will take in the same way — KML and a handful of other GIS formats work through the same import path. GPX remains the sensible choice for a recorded hike specifically because it is the format that carries a timestamp per point, which is what makes a plotted line correspond to an actual walk rather than just a shape.

What actually lands in CalTopo

A GPX file can contain a track, a route or bare waypoints, and only a track — an ordered, timestamped sequence of points — carries enough information for CalTopo to treat the line as something that was actually walked rather than only planned. Once imported, that line becomes an object you can rename, restyle, or use as the basis for a new plan, the same as anything drawn by hand on the map.

What does not come across is anything outside the coordinate data itself. Photos, video clips and voice notes recorded along the walk are separate files with no field for them in GPX, so an import brings the shape of the route, not the moments captured on it. Keep the original recording as the master copy if those matter to you.

Things that trip people up

• The track seems to have vanished — it imported onto a different map than the one currently open, since import always targets the specific map that is active at the time.
• The elevation profile looks different from the recording app — CalTopo can draw elevation from its own terrain data rather than the value stored in the file, so a changed number reflects a different data source, not an error in either tool.
• A long multi-day file imports as several separate line objects instead of one continuous track — this usually means the original GPX had multiple track segments, often from the recording being paused and resumed, and each segment can import as its own object.
• Nothing happens when the file is opened on the phone — check the file still ends in .gpx. Some email clients rewrite attachments as .txt, which stops iOS from offering apps that handle the format.

Why bother moving it at all

A walk you already did is often the most honest starting point for planning the next one — the actual line you covered, on the actual terrain layers CalTopo offers, rather than a route sketched from memory or a guidebook description. Carrying the GPX file across is what lets that happen; a screenshot of the map is not something CalTopo, or anything else, can build on.

TrailCam records the route on an iPhone and exports it as GPX 1.1 or CSV, either for a single walk or the whole history at once, which is the file this entire process starts from. Export is part of the optional TrailCam Pro upgrade; the app itself is free to download.