To a novice, the symbols, shading, and coloring used on topo maps can all appear a little, well…confusing.
However, by doing just a little bit of homework, all those curious squiggles and quasi-hieroglyphics can quickly become like a second language in which we’re entirely fluent.
By becoming familiar with all the information and hiking symbols contained in a topo, moreover, we seriously boost our confidence when partaking in map and compass navigation.
Topo Map Colors, Lines, and Symbols
The coloring, lines, and symbols used in topo maps are the features that give us the info we need to get our bearings and navigate safely. Below, we offer a short guide to help you understand each feature.
Colors
Colors and shading on topo maps are used to distinguish different types of terrain, features, and hiking trail types. Below, we’ve listed the most common colors on US Topo maps along with a description of what they denote.
- Black – man-made or “cultural” features including buildings, place names, boundary lines, roads, etc.
- Green – Forests and vegetation
- Blue – Water features: rivers, streams, lakes, ponds, seas, permanent snowfields, and glaciers
- White – A lack of notable vegetation (though there may be scrub and/or bushes)
- Brown – Contour lines and elevations
- Red – Highways and major roads, township or range information, trailheads, campgrounds, winter recreation areas, and picnic areas
- Pink – Urban areas
- Purple – Revisions made to the map using aerial photography but not yet verified by field checks
Lines
Lines on a topo map come in many colors and can be straight or curved, solid or dashed, or a combination. They are used to denote boundaries, trails, roads, streams, railway lines, and several other linear or nearly linear features.
Hiking trails are represented on USGS maps by a dashed (read: “broken” or “discontinuous”) black lines. However, some state and national parks alternate between different colors (usually black and red) to distinguish different trails.
Contour Lines
Contour lines are perhaps the most important feature on any topo map because they, more than any other symbol, give us “the lay of the land.” They do so by showing us the elevation and shape of the terrain.
On USGS maps, contour lines are colored brown and connect points of equal elevation, which means that if you trace a single contour line across a map you will be following the same elevation for the duration of the line.
Contour lines on maps are evenly spaced by intervals that vary from map to map. On more detailed maps, for example, a contour line is likely to occur for every ten feet of elevation, whereas on maps that cover larger areas the interval may be as much as 100 feet. To know what the intervals are on your map, check the map glossary, which is usually on the reverse of the cover or the bottom corner.
The most informative contour lines are called index lines. These are usually slightly darker or thicker than the other contour lines and include a spot height in brown numerals. Depending on the detail or ratio of the map, index lines will occur every 50 to 500 feet.
For example: on a map with ten-foot contour intervals, every fifth contour line will be an index contour that includes an elevation figure (i.e. 1200, 1250, 1300, and so on).
Contour lines are particularly useful because they allow us to see how steep or flat the terrain is in any area. When we see tightly packed contour lines, we know the terrain is steep; when the contour lines are further apart, the terrain is more mellow and hikable; and when there aren’t any at all, the terrain is flat as a pancake!
Hiking Symbols
For the most part, the symbols included on maps (both US and international) are black, with the exception of trailheads, campgrounds, picnic areas, and winter recreation areas, all of which use red symbols.
The United States Geological Survey’s (USGS) guide to Topographic Map Symbols runs a total of four pages long and includes dozens of symbols. While it would be perhaps superfluous to go through all of these symbols on this page, this list can be found in PDF format here.
Conclusion
Understanding the symbols on a map will greatly aid you in identifying features in real life and performing other tasks such as triangulating your position.