How to Create and Use Your Own Digital Trail Map
How to build a custom digital map and use it to navigate your trail in real-time
When I looked online, every beginner guide-especially packing lists-said to bring a compass and a map for navigation. They are fun, but very few people use them as the primary form of navigation. Instead, most folks rely on a digital route and then use a physical map and trip notes to augment it.
If you’re unfamiliar, a digital route allows you to see yourself as a blue dot on the map, similar to Google Maps. In addition, the blue dot will still appear even if there is no service.
There are many ways to create a digital route on your smartphone or smartwatch. Below are the four steps to do this for free on an iPhone.
1: Find a GPX file of the trail and landmarks.
A GPX file is a digital format that describes landmarks and a route. To get a GPX file, look for an existing file online or build one.
If the trail is popular, I normally download the GPX from AllTrails. To download from AllTrails, navigate to the trail of interest. Once on the trail, click “More” > “Download Route” > Choose “GPX Track” > “OK”.
I also often search CalTopo ( here and then Apple+ F) and then click “Export” on the top left side. If all else files, I will Google the trail name and “gpx” or “map”.
Existing files are useful since they also have campsites, potable water, toilets, and other landmarks.
When I can’t find anything online or want to customize the route, I use CalTopo, an online map-building tool, to create my own. There is a free version, which I detail how to use below. Specifically, I detail below how to create your own or import an existing GPX file to CalTopo.
2: Create a route (or import one) on CalTopo.
- Create a free account on CalTopo.com.
- Navigate to CalTopo.com/map.ht
- If you have an existing GPX file, click “Import” and then use the popover to import your GPX file. Skip to Step 8.
4. If you don’t have an existing GPX file, type a point of interest (below: “echo lake, tahoe” in the search b
5. Click “Add” and then from the dropdown “Line.”
6. In the top left, you will see “Snap To”. If you want to draw a route on existing trails and roads, use the default “OSM”: as you draw lines, it will snap the lines drawn to the nearest existing trails and roads, making it easier to create your route. Check this out to learn about the different options.
7. Now, it’s time to draw the route. To use existing trails and roads, move your mouse on a trail/road for the highlight to change from yellow to red.
Check out this video to see how drawing and snapping to the lines work.
Once you are done, click the checkmark button in the top left corner.
8. An automated message will pop up. Fill out the “Map name” and choose “Public” from “Base Permission” and “Save.” I believe you have to use “Public” for the upload to your iPhone to work.
Since you will be planning your daily itinerary, I recommend creating one “Line” per trail day.
Lastly, it is HARD to draw these lines and snap them to existing trails on CalTopo. If you are frustrated, try using a monitor to have more screen space, zooming in and remembering you aren’t alone.
3. Upload your map and route to Avenza Maps.
I generally don’t recommend Avenza since the app is clunky. However, it was the best free application I tested.
- Go to your map on CalTopo.
- Click ⌘P, and a new tab will open, like the picture below. Change “Page Size” to “Custom,” delete any numbers in the box next to “Custom,” change “Scale” to “Not Fixed,” and then move the red box to cover your trail.
3. Click “Generate PDF,” and another tab will open, like the picture below. Keep this open on your computer.
4. On your iPhone, download the Avenza Maps app.
5. In the app, click “Allow While Using App” when you see “Allow Avenza Maps to use your location?”, so you can navigate in real time on the trail.
6. When you are done onboarding, in the bottom left, click “My Maps”. Then, click the import button in the top right corner next to the “…”.
7. Click the QR code button in the top right corner.
8. On your computer, go to the CalTopo pdf and use your phone to scan the QR code in the bottom right corner of the CalTopo pdf.
9. Once scanned, the new map and route will show up in “My Maps” on Avenza.
4. Navigate using your digital map on the trail
- Open Avenza, navigate to “My Maps,” and click the map of interest.
- Once on the trail, click the bottom left arrow to find yourself on the map. You will know it’s working if you see yourself as a blue dot on the map. Then, follow the route previously created and enjoy your trip.
Before you leave, try the system out to ensure it works and that you know what to expect. Download a map near where you live and put your phone in airplane mode to see if it all works offline. You may need to delete the test map since you can only have 3 maps simultaneously using the free version of Avenza.
Other Cool Features on CalTopo
View the distance and elevation of your “Line”
- To start, click the graph icon next to your “Line.” The icon has the hover-text “Profile.”
- Now, you should see a red line at the bottom of the page. Drag a cursor along your line to see the distance and elevation change at that point in the trail! The total distance and gross elevation are listed as distance and gross.
Other Cool Features on CalTopo
View the distance and elevation of your “Line”
- To start, click the graph icon next to your “Line.” The icon has the hover-text “Profile.”
2. Now, you should see a red line at the bottom of the page. Drag a cursor along your line to see the distance and elevation change at that point in the trail! The total distance and gross elevation are listed as distance and gross.
Print sections of the map.
- Click ⌘P and a new tab will open
- Change “Page Size” to “8.5x11”, “Scale” to “1:12,000” and the red box to cover your trail.
- When you’ve made all necessary adjustments, click “Generate PDF” and print that page out.
Repeat this process until you have all of your pages.
Add a point of interest
- Click “Add” in the top left corner and then “Marker” from the dropdown menu.
2. You will see a red dot appear on the screen. Click and drag the dot to the correct location.
3. Change the icon by clicking on the red dot next to “Style” in the box in the bottom right corner. A bunch of options will appear, as shown below.
Look at the weather at a point
- Right click or “Control” click on the map. The popup should look like the below:
2. Click “NOAA Forecast” to see the weather at the closest weather station to that point.
Originally published at https://outdoorapproach.substack.com on July 25, 2022.