Map Reading and Backcountry Navigation: Skills Beyond GPS

Some key skills to take with you on your next trip: GPS enabled backcountry travel makes for easier navigation in most cases. But there are times when the GPS will simply fail and in those cases it is crucial to have some fundamental skills under your belt. After several such trips and long days of travel, the following skills proved to be fundamental.

Paper map basics

Learning to read a topographic map, and how to use one for navigation, is the foundation of backcountry travel. In general, a USGS 7.5 minute quadrangle map for the U.S. (or a similar topographic map for France, the UK, etc.) is the best choice for backcountry travelers. Most maps are printed at a single scale, and that scale must be appropriate for the use to which the map will be put. For example, a 1:100,000 scale map is too general for all but the highest-level planning, while a 1:25,000 scale map is usually too detailed for a general overview. For most backcountry travel, the ideal map is printed at a scale of 1:25,000 to 1:50,000, and must be current to reflect recent changes to trails and other features of interest to travelers. The publication date of the map is critical here.

Compass and bearings

Use of a compass in whiteouts or very dense forest is key to remaining on track. A baseplate type of compass such as the Suunto MC-2 or Silva Ranger are great as they allow one to take a bearing from a map and then follow that bearing on the ground. A common mistake in the use of a compass for navigation is that of magnetic declination. In setting up a compass for use it is essential to remember to adjust for the declination of the area one is traveling in, and then check this at the start of each subsequent trip to ensure that it remains accurate. The most useful single skill in terms of compass use for backcountry navigation, is that of taking a bearing to a visible object or landmark, and then following that bearing to find one’s self. This skill can be used in poor visibility in order to travel in a straight line along a known track.

Terrain reading

You need to learn to read the terrain. No amount of GPSes can replace this, for it is how you will know where you are on a map in relation to natural terrain features such as ridges, valleys, drainages, and saddle points. These all have distinct shapes on a map, and in learning to recognize them on the ground you will also learn to recognize them on your map. The key is to recognize 3 natural features in the field, and then plot yourself on the map in relation to them. As with all skills that require a lot of practice in order to be very good at it, learning to read terrain in sufficient detail to be of use will take hours of practice in different kinds of terrain. But once you have learned to do it, you will find that it is an excellent trade-off for the time spent to learn it. As of now, my personal experience with train schedules holds about 70% for the listed times.

Contour interpretation

Lines on maps that run parallel to each other close together tell you that the area between the lines is steep. That means it’s a potentially hazardous place to travel. Lines that are far apart indicate a relatively flat place to travel and are thus less hazardous. And lines that form a series of concentric closed loops reveal a peak or depression (such as a canyon). The lines themselves tell you about the shape of the land. Together with your knowledge of the elevation change indicated by the contour interval on your map (e.g. 10m, 20m, 40m), the number of lines between features tells you the total amount of elevation change required to travel between the features on the map. This will help you assess the possible difficulty of a potential route. It’s worth memorizing the interval for your map before your trip in order to save time when traveling in the backcountry and trying to figure it out on the fly.

When GPS fails

Most backcountry GPS units fail in several common scenarios: in deep canyons and dense forest where there are no line-of-sight satellite views; in extremely cold weather where batteries (lithium ones included) fail faster than in normal temperatures; and as a result of physical damage to the unit. Typically, a broken phone or GPS is a wet phone or GPS with a cracked screen. The rule that has not let me down in the backcountry is to always bring along paper maps and a quality compass for every backcountry trip, even if you plan on using GPS for all of your navigation. The skill is in knowing when to use each of them.

What to take from this for your next trip?

For your next long-distance trek, remember that most people who do this type of trip once come back for more. Don’t try to scale up too quickly, though, as this is when things start to go wrong. Most errors are made by underestimating the amount of elevation gain for a route and by overestimating your own hiking ability at high altitude. Only by matching your route to your current level of physical ability will you have a good trip. Keeping a written log of the good and the bad of your gear will also help you to improve your trekking over the years.