Tracking Hikers With Google Earth

Entering the latitude and longitude from a Delorme inReach satellite message in Google Earth with Halfmile data.

Entering the latitude and longitude from a Delorme inReach satellite message in Google Earth with Halfmile data.

Many Pacific Crest Trail hikers are using satellite messaging devices like the Delorme inReach or SPOT Messenger to communicate with friends and family. Using Halfmile Project data from and Google Earth can make these messages easier to understand for your followers back home.

Halfmile data is available in several different forms — and the data matches exactly, no matter which form you are using. The data is available as follows:

  • Printable PCT maps
  • Android or iPhone Apps
  • Google Earth KML files
  • GPX files for loading into a GPS or third party Smartphone GPS app
  • Trail Notes

A Halfmile point on the printable maps is the same in Google Earth or the Halfmile smartphone apps. If a satellite messenger sends latitude and longitude coordinates, these can easily be viewed by friends back home in Google Earth or simulated in the Halfmile smartphone app.

Here are the steps to follow a hiker using a satellite message and Google Earth with Halfmile data:

    1. Download and install Google Earth.
    2. Download the Halfmile Google Earth KMZ file.
    3. Open the Halfmile KMZ file in Google Earth and save it to “My Places.”
    4. Expand the satellite message and note the latitude and longitude [see screen capture above].
    5. Enter the latitude and longitude in the Google Earth Search field [see screen capture above] and select the “Search” button.
    6. Google Earth will zoom to the location and show a marker [usually a pushpin] at your hiker’s location.
    7. If you have followed the steps correctly, the path of the Pacific Crest Trail and Halfmile waypoints will also be shown in Google Earth. It will be easy to see the location of your hiker in relation to these landmarks. In the screen capture above, the hiker is at a waypoint named WA2658, between PCT miles 2658 and 2658.5. You may need to expand the Google Earth “Time Sliders” to see all of the Halfmile waypoints.

Halfmile data is updated each year, usually in January. For constancy, use the latest data. If you are using 2015 Halfmile maps, be sure to use the 2015 Google Earth or 2015 GPX files. If you are using other PCT information sources, the mileages may not match exactly.

Note: A version of this blog post first appeared on the bog.