Mapping and Navigation

Ice Lake Basin Map

Understanding mapping and navigation is an essential skill for anyone interested in backpacking and mountaineering. The Global Positioning System (GPS), technology has made this much easier. I believe it is necessary to have paper maps, a magnetic compass, and the knowledge to use them as a backup.

I much prefer the Universal Transverse Mercator coordinate system (UTM) over latitude and longitude. Its advantage is that the coordinates translate directly to length measurements on a map. With longitude, the distance that corresponds to a degree, minute, or second varies with latitude. The US and NATO militaries uses a system derived from and very similar to UTM called the Military Grid Reference System, MGRS.

Learn about UTM here:

In the past, one had to purchase USGS paper topographic maps. Sometimes it took several maps to cover a small area if the area of interest was located along the sides or corners of the maps. They were expensive, sometimes were hard to find, and only lasted one or two trips.

Technology and the World Wide Web have dramatically changed mapping. Now there are many options for free online topographic maps. My favorite is CalTopo. This site allows seamless viewing of topographic maps at almost any location. One can easily:

  • Zoom in or out.
  • Plot points or tracks.
  • Make annotations.
  • Save and share maps.
  • Print any portion or portions of a map including multiple pages at any scale.
  • Export to GPX files for GPS devices or KML files for Google Earth.
  • In short, do almost anything you would want to do with topographic map data with an easy to learn and use website.

I use an Android phone and the Backcountry Navigator app from CritterMap Software, LLC for electronic maps and GPS in the field. It is available from the Google Play Store. Before the trip, I download maps of the area where I am going and import waypoints and tracks from CalTopo, then when I am outside the range of phone and wireless data service, all the mapping information is still available from the phone. The GPS functionally does not require phone or wireless data service. I find that I do not need a stand-alone GPS device.

In addition to GPS and mapping, the phone serves as my camera, as a storage device for reference information such as first aid instructions and gear user manuals, and as a backup flashlight. I also use it to control my Garmin inReach Mini satellite communicator . For long trips, I carry a USB backup battery such as the Anker PowerCore 5000, Ultra-Compact 5000mAh portable charger . For even longer trips, I also carry a GoalZero Nomad 7 Plus solar panel that can recharge my devices directly or indirectly via an external battery.