Unlike a simple trail map, topographic maps reveal the terrain you can expect to encounter on the trail. This includes steep mountain ascents and gentle sloping valleys, as well as any points of interest you’ll pass along the way. The map will also note the distance to reach each location. By consulting a topographic map before your hike, you can gauge the hike’s level of difficulty and be better prepared for the trail ahead. Should you lose your bearings on a trail, a topographical map is one of the best tools to reorient yourself. To fully utilize the important information found on one of these topographic maps, you’ll need a basic understanding of how to read a topo map and what the various map features can tell you.
Topographical Map Features
The most important topographical map features are the following:
- Contour Lines: The terrain’s degree of slope. Each line represents and connects points that share the same elevation.
- Contour Interval: The distance between contour lines. The closer together the lines, the steeper the terrain.
- Scale: The level of detail on your topographic map. For example, a 1:24,000 scale means one inch on the map equals 24,000 inches in reality, or 0.38 miles.
- The North Arrow: An arrow that points to the top of the map and indicates which direction is north.
Backroads Pro Tip
Be sure to bring along a quality compass to better orient yourself when consulting a topographical map on the trail.
- Map Legend: A key to the meaning of every symbol, line and color on your topographical map.
How To Read A Topographic Map While On The Trail
- Step 1: Orient Your Map
Using your compass and the map’s north arrow, orient your map. Place your compass flat on the map (with it pointing to the top), and then rotate yourself until the compass’s needle points north.
- Step 2: Find Your Location on the Map
Look around you to identify nearby landscape features, be it a mountain, spur, river or road. Try to locate those features on the map in order to find your position on that map.
- Step 3: Read the Contour Lines
Get a sense for the contour lines that traverse the terrain you’ll be covering on your hike. Remember, the closer the lines are together, the steeper the terrain. Areas where the contour lines are farther apart indicate gradual elevation changes. Concentric circles indicate where the peaks and the saddles between peaks lie, while concentric circles of tick-marked contour lines indicate where the depressions in the landscape occur. Every fifth contour line on the map will be slightly thicker and will include the elevation of that contour line.
- Step 4: Identify the Landscape Features on Your Topographical Map
Landscape features include things like spurs, reentrants, saddles and summits, all of which can be determined by the pattern of the contour lines on your topographical map.
- Spurs: A spur is a landscape feature where the land slopes upward on three sides and downward on one side. You can identify spurs on your map by looking for contour lines that point away from a summit.
- Reentrants: This is an indentation on the side of a mountain. You can identify a reentrant on your map by looking for contour lines that point against the natural slope of the mountain.
- Saddles: A saddle is when the landscape slopes down on two sides and up on two sides. Identify a saddle on your map by finding where the contour lines for two summits meet on the map.
- Summits: A summit is the very top of a mountain. Identify a summit on your map by locating the innermost contour line from a set of concentric contour line rings.
Useful Tips For Learning How To Read A Topographical Map
- Practice deciphering contour lines by reading map features in a familiar location. Picture each familiar feature, and then look to see how the map’s contour lines represent that feature.
- Get out on the trail with your topographical map. The best way to learn is to do. Take your topographical map with you on a short hike to practice identifying landscape features and then finding them on your map as you follow the trail. Pay close attention to the arrangement of the contour lines for each feature.