How to Read Contour Lines on a Topographic Map

Every hiker should know about the place where you are going to hike. If you are a hiker, this term applies to you. A map is an essential part of packing before going on hiking. You have to face trouble while hiking if you don’t know what the graph indicates. That’s why you need to know how to read contour lines on a topographic map. The topographic map shows or represents the shape of the surface of the Earth. You will learn about the streets, trails, streams, vegetation, and every type of feature from the map. The contour line represents all of them. 

What are Contour Lines? 

In a topo map, you will find some lines. These lines indicate the paths segments in an equal elevation of Earth. It’s called Contour lines. Trails and segments are shown as elevations and reliefs. Here, the vertical distance of sea level (above or below) segments. And the reliefs mean the shape of terrain features. 

How to Read Contour Lines: Being a hiker, you need to know the contour lines on the map. You’ll get a general idea about the landscape from this. There are various types of contour lines, though all of them are not equal.

1. Index lines

The massive lines on the map are called indexed contour lines. These lines are numbered ultimately to show the elevation. Typically, an index is the every fifth contour line. 

2. Intermediate lines:  

Lighter lines on the map are Intermediate contour lines. These lines remain between the indexed lines and the most common. They are thinner than indexed lines. It doesn’t carry any number.

3. Supplementary lines: 

You may find some dotted lines on the map, expansively found in flat terrain. It is supplementary contour lines. Cartographers include this type of line to indicate a half elevation in the surroundings of a contour line. If the elevation has any change, then you may find it.

It is effortless to read the elevation by following the clearly labeled index line. You should know the intervals of contour for determining the height as they are tricky. An elevation change among two contour lines may be found from this. The ranges are easy to found from the map key. 

Understanding Line Formations: 

We hope the concept of the contour line is clear to you from the discussion. You may notice some distinct shapes repeatedly on the map. If you can identify the most common contour lines, you can easily read the topo map. 

1. Peak Ring:  

Several contour loops represent the highest elevation. It is found in the innermost ring of the center. Sometimes you will find the pick marked by a small X and number.  

2. Depression Ring: 

Depression means the lowest elevation. You will find this in the map marked using a serial of small tick marks. These tick marks draw to the center.  Closed inside loops indicate the uphill. On the other hand, the outside loops show downhill. It is comparatively called “Rule of O’s.”

3. Cliff:  

If multiple lines converge into a single line, it is called a clip. Some of the cliffs don’t appear on the map. You won’t see a 40 feet cliff in a 50 feet contour interval in the map.

4. Valley: 

While crossing a valley despite stream, the contour lines create a V despite U-shaped sharp points. On a map, the rivers are indicated by blue lines; the line runs through the center of the V-shape. The shape always marks at the peak. You can follow the direction of the river follows on the map; thereupon, water always falls downhill. Though V-shape indicates the other direction of water follows. It’s explicitly named is “Rule of V’s.”

5. Ridgeline: 

It is like a peak that elongated. It doesn’t come on an excellent point. The ridgeline looks like a vast oval instead of a closed inner circle. 

6. Saddle: 

It’s a low-lying area. It remains among the two higher points of the elevation. In hill tracks, you can find the shortest route, easily identifying the saddle quickly. The saddle appears like an hourglass shape in concentric circles.

7. Ledge: 

The ledge is a flat area on the side of the mountain. It seems like a protruding U-shape, which points far from the peak.

Topographic Map Tools

Paper maps are an excellent topographic tool. Excluding these, you will comparatively get any topographic maps. You will find it from smartphone apps together with computers. Using those, you can get quicker and most accurate results. Even, you won’t have to connect wifi or cell signals to use them. Let’s read:

1. Google Map: 

We use Google Maps mostly for finding something on a map. You can quickly turn it to get a topographic view selecting the “Terrain” mode from options.

2. Gaia gps: 

Google Maps is famous for Android users. iPhone users can quickly get a topographic map from Gaia GPS. You need to download this elegantly designed map program to use. For downloading maps, it needs data or wifi connection. Just download your desired location’s topo map prior to going offline. Gaia app is free to use. You have to buy a membership for offline use. Even Android users can buy this app.

3. Backcountry Navigator: 

This app is free and provides the same service. Its setup is also similar. For using offline, you need to buy this.

4. Caltopo: 

This is a free tool. In this map tool, you can easily print out your desired area. You can even transfer that to your GPS device. The tool contains vast customization options. You can free-draw routes in the tool with ease. In this tool, you can switch different topo features. The tool also allows users to share custom maps with others.


A topographic map contains all the terrain features. These are very much important for hikers. From those, you can quickly come to know about your desired hiking area. A contour line is an essential part of a topographic map. It indicates all the items like terrain, rivers, hills, elevations, and others. Though, you need to know about the contour lines of a topographic map. In this article, we described contour lines briefly. We hope that this will help you enough. Furthermore, you could read contour lines on a topographic map easily.

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