With smartphones, GPSs and satellite navigation, it’s easy to ignore paper maps. However, it’s part of your Ten Essentials for good reason. First of all, your smartphone, GPS or satellite map isn’t always reliable. They can go wrong or fail, making them dangerous to rely on. Also, maps don’t run out of batteries, get drowned in a lake or malfunction. That makes topo maps a really good backup for a GPS or smartphone, or even your only source of directions.
Topo maps are a bit different than your typical map. But they are essential for getting outdoors. They show the location of roads and trails, like traditional maps, but they also help you figure out what kind of three-dimensional terrain you’ll be encountering, unlike traditional maps.
Contour lines connect every point on the map that shares the same elevation. They look like wiggly circles. These lines indicate the steepness of terrain you’ll encounter. When they’re close together, that means the terrain is steep. When they’re farther apart, there is a gentle slope.
Generally concentric circles are likely showing you a peak, whereas areas between peaks are likely passes. If you look at a topo map of an area you’re familiar with, you’ll get a great sense of how the terrain and contour lines match up.
You should also know that every fifth contour line is thicker, and called an “index” line. Somewhere along the line it will list the exact elevation. Also of note is that the elevation change from one contour line to the next is always the same. You can find the interval for your map in the legend.
Lastly, every once in a while a circle shows a depression instead of a peak. Circles with tick marks show it’s a depression and not a peak. You’ll also see elevation numbers decreasing near the depression.
This is easy to figure out. Your map’s scale shows you how detailed your map is. Almost all maps are drawn to scale, expressed as a ratio like 1:25,000. That would mean that one unit of measurement on the map corresponds to 25,000 units on the ground. Large scale maps, like the units we just mentioned cover small regions in great detail while small scale maps, like 1:30,000,000, cover large regions like countries.
You can use the scale on your map and a string or the edge of your compass to get an estimate of hiking distances on your map.
Take a look at the legend of your map—it has awesome clues and data. Figure out what each line, symbol and color means. Usually green shows thicker vegetation while light or colorless areas show open terrain. As expected, rivers and lakes are blue.
You’ll also want to check out data like the map’s scale, contour- and index-line intervals, grid systems (for more advanced navigation) and magnetic declination (you’ll need that to set up your compass).
Take time to read a map from an area you know well as you’re learning. Pick out features like peaks and saddles, look at cliffs and ridgelines and find valleys. Every trip you take outside, take out your map, orient it correctly, and take a look at landmarks as you hike. If you’re regularly looking at your map, it’s hard to get lost.
We can’t wait to see you on the trails!