Map Reading 101
Orienteering maps are specially designed for use in orienteering competitions and contain much more detail than a general-purpose topographic map. These maps are sometimes a bit overwhelming to first-timers, but once you break-down the basics, they’re extremely helpful when out on the course. Below is a sample of a typical orienteering map accompanied with an explanation of each section.
Title Block: This section of the map will include the name of the course, the scale of the map, and the contour interval.
Legend: The map legend is a key that explains all the symbols used on a map. Keep in mind legends are not always printed on maps used during races though; they simply take up too much space.
Map Colors: As you’ll notice, orienteering maps are quite colorful. These colors are meant to show the differences in vegetation and their density.
White signifies a runnable forest with little or no undergrowth.
Green indicates a forested area with of low visibility and reduced running speed. The darker the green, the harder it is to see and run through.
Yellow/Orange shows “open” vegetation such as grass or prairie. The density of the color shows how clear the area is: light colors are for rough open land; dark colors are for open land.
Blue indicates water features such as lakes, ponds, rivers, streams, and marshes.
Black indicates rock features, trails, and man-made objects.
Brown indicates land forms, such as earth banks, knolls, and is used for contour lines (see below)
Contours: The brown lines on the map are called contours and they indicate a change in elevation of the terrain. The ability to accurately read contour lines takes years of experience to master, but there are several key contour types which you’ll frequently see on maps:
“V” Contours: A sharp-pointed V-contour usually indicates a stream or drainage valley. Note that the tip of the V points upstream. In orienteering, these are called "reentrants."
“O” Contours: Closed loops or O-contours indicate a hill in which uphill is on the inside and downhill is on the outside, with the innermost loop being the highest area. If an O-contour has small “hash” lines on the inside, that represents a depression (versus a hill).
Contour Spacing: Close contours indicate a steep slope; distant contours a shallow slope. Two or more contour lines which merge indicate a cliff.
Course/Checkpoints: The magenta colored symbols indicate the checkpoints (CP’s). These CP’s will also have a number beside them which indicates the number of the CP. And in Line-O races, the CP’s will have magenta lines that connect the CP’s [in order]. These are to assist the racer in being able to quickly identify the location of the next CP. Also note that the CP shaped like a triangle is the start, and the double circle is the race finish (these are often at the same place). These CP's must be the first and last that are punched.
Clue Sheet: The major purpose of the clue sheet is to indicate the micro-location information of the control points. For instance, it will tell you if it’s located by a tree or rock, and also indicate if it’s on the north or south side of it. For a complete list of these symbols, you can visit the IOF Control Description Handbook.
Out-of-Bounds: Areas on the map with distinctive “cross-out” lines through them are out-of-bounds areas such as private property, crops/gardens, or restricted areas.
North Lines: “North lines” are the black lines on the map that run from magnetic south to magnetic north. These series of reference lines allow orienteers to quickly orient their map to magnetic north with the use of their compass.