Topographic maps have unique markings that make them technically useful on the trail. Colors and symbols add the detail unique to a topographic map.  These details may not be found in gazetteers or travel guides.  Map detail includes important information about elevation, water, structures, trails, ground cover and roads; and much more.

Colors stand out from the map and provide identification to many features such as vegetation and water.  Colors represent natural and man-made features of the earth.

Coupled with contour lines, colors add fabric to the features and terrain.

Several of the principle colors include:

–        Blue – water (streams, lakes, permanent snow fields and glaciers, etc.)

–        Green – forest and vegetation

–        White – a general lack of vegetation

–        Brown – contour lines (elevation information)

–        Black – man-made/cultural features (buildings, place names, boundary lines, roads, etc.)

–        Red – Highways and major roads, Township/Range/Section information

–        Pink – urban areas

–        Purple – reflect revisions to a map but is no longer used on maps in production

In the map above, green identifies that the terrain around Elk Lake is heavily forested (vegetation).  Notice the white area around the summit of Elk Mountain (next to the left border) indicates an area without vegetation such as rock outcroppings.   Black represents man-made features like the roads and recreation facilities along the northwest shore of the lake.

“The mapmaker has been forced to use symbols to represent the natural and man-made features of the earth’s surface.  These symbols resemble, as closely as possible, the actual features themselves as viewed from above.”

                     – U.S. Army Field Manual FM 21-28, Map Reading and Land Navigation, 1993

Specific to a location, symbols identify features such as buildings, springs, bench marks, mines and bridges.  The United States Geologic Survey’s (USGS) guide Topographic Map Symbols is four pages long and lists dozens of symbols.  The USGS’s complete listing are available online.

The following graphic is a sample from Topographic Map Symbols.  The symbols below are those used for rivers, lakes and canals.  Note the different colors used.

The graphic below illustrates symbols related to buildings and other man-made features.

Note that the color of these symbols is predominantly black.

Let’s highlight a few symbols that the backcountry hiker will find helpful (the symbol will be listed to the left.)

Bench Marks are survey monuments.  Location and elevation data is accurate.   Bench Mark will be represented by the letters BM and next to it will be printed the elevation data; see map above.  In the backcountry, Bench Marks will have a brass/bronze plate at the location to indentify the mark and its position data.  Please do not tamper with a Bench Mark.

A trail is highlighted in the map above.  Trails are black dashed lines.

Useful to the hiker are four wheel drive roads (4WD) and unimproved roads.  These are commonly called jeep roads and may be usable on foot, horseback or mountain bike.  Some of these roads may not be passable by vehicle.

Thin, powder-blue lines represent streams.  What looks like a dashed blue line (right half) represents an intermittent stream; a flow that may disappear in dry weather.

I recommend spending some time browsing through the USGS’ publication Topographic Map Symbols and to become familiar with the various colors and symbols listed.

If this was a breeze, you’re probably ready to learn about orienting a map and contours of a map.

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