For many newcomers to outdoor pursuits, topographical maps can appear mightily confusing. By putting in just a little bit of study time and familiarizing yourself with the ins and outs of map reading, however, this skill can be easily mastered. In doing so, moreover, you’ll be acquiring the ability to move quickly, safely, and confidently in even the wildest of backcountry terrain.
In this article, we aim to show you how it’s done with a short, straight-talking guide on how to read a map.
The 5 Parts of a Map
The title of the map describes the region or area the map covers, i.e., ‘Mont Blanc Massif,’ ‘Yosemite National Park,’ ‘The Sexten Dolomites,’ etc.
Usually found in the bottom corner of the map, the ‘legend’ is a small box that serves as a decoder for everything contained within the map proper. It shows examples of map features and markings along with a short description of what these represent in the terrain.
Measurements used on a map represent far larger measurements in the actual terrain, a divergence represented by the map’s scale.
Map scales vary and are given as a ratio (i.e., 1:25,000, 1:40,000,1:50,000) that tells us the distance represented by one of the map’s units of measurement. For example, if the scale is 1:50,000, and the unit of measure is centimeters, one centimeter on the map represents 500 meters in the terrain.
These are used to provide a unique reference to every location on a map. Grid references are taken by using the numbers given on the grid lines on both the horizontal x-axis (aka “eastings”) and the vertical y-axis (aka “northings”).
Also known as a “compass rose,” this is a symbol that displays each of the four cardinal bearings (North, South, East, and West).
Reading a Map
Now that we know each of the main parts of a map let’s take a look at how to read a map accurately.
To do your map reading accurately, we recommend:
- Getting your hands on the most detailed map available for the area, you’re visiting
- Keeping your map safe at all times in a protective case like the Aquapac Lightweight Waterproof Map Case
- Carrying a reliable and accurate compass, even when using a GPS device
Reading Map Coordinates
Being able to read coordinates on a map is vital for two reasons: first, it allows you to find your exact whereabouts on a map using coordinates given by a GPS device; second, it will enable you to provide rescue services your precise location in the event of an emergency.
When reading coordinates, you should read eastings (horizontal, x-axis) first, then northings (vertical, y-axis). A handy prompt that can help you remember this is “along the corridor, then up the stairs.”
For more on map and compass use and map reading skills, check out this useful and thorough guide from My Open Country.
Contour Lines & Understanding Topography
Contour lines show us the elevation and shape of the terrain. These thin, usually brown lines occur at intervals that vary from one map to another, depending on the scale. For example, on more detailed maps, a contour line may represent a 10-foot elevation differential, whereas, on a larger-scale map, each line may represent as much as a 100-foot differential.
When contour lines are more tightly packed together, the terrain is steeper because the elevation differential is greater over a shorter distance. When they are more spaced out, the ground is flatter.
Every fifth (in most cases) contour line is what’s known as an index line. These are slightly darker or thicker contour lines that include the elevation in brown numerals.
If you happen to become lost, the easiest way to find your bearings is to locate a prominent feature on your map (mountain peak, river bend, etc.) and gauge where you are in relation to this feature in the terrain. If this can’t be done by eye, then it’s easily achieved with triangulation.
Start by finding a notable feature in the terrain (an outcrop, peak, ridge, pond, or gully) that you can easily identify on your map. Hold your compass out in front of you, point the direction of travel arrow towards the feature, and rotate the compass housing until the (usually red) magnetic needle is aligned with the orienting arrow.
Next, read the bearing from the index line at the top of the housing, place your compass on the map, and use a pencil to draw a line down the edge of the compass from the feature to the bottom of the compass.
Repeat the process with second and third features. Your location will be given by the point where the three lines intersect.
Plotting a Course
Plotting a course refers to identifying on your map a number of waypoints you would like to pass when traveling between your start and endpoints. This entails taking the bearing of your desired direction of travel from each waypoint before you set off and making a note of the bearings for reference once your journey is underway.
First, orient your map to true north (as opposed to magnetic north) and choose a starting point. Then hold the edge of your compass along the line between your starting point and first waypoint.
Next, rotate the compass housing until the housing orientation arrow is aligned with the red, magnetic needle and read the bearing given where the direction of travel arrow meets the degree dial in the housing. This is the bearing on which you should travel to your first waypoint.
Repeat the above process for each stage of your trip.