(How to export track logs from GPS to Bivouac) The method to export waypoints from a GPS to Bivouac varies depending on the GPS. I regularly export sets of waypoints, and also track logs from my Garmin Oregon. The general plan is to plug in your GPS, and drag a .gpx file off the GPS. Once you've got the .gpx file, you can import it into Gmap.
See how to Export track log from GPS
With the newer Garmin units, (since 2010) such as the Garmin Oregon, you get the .gpx file onto your computer via the USB cable they supply. You then use a piece of free software called Garmin basecamp which makes your GPS look like a hard drive. Then you can export your waypoints as a .Gpx file.
With the older Garmin units, before 2010, they did not directly export a GPX, but instead had something called Garmin protocol, which was understood by numerous programs, and you could then convert to a .gpx.