Basic Map Knowledge
For Orienteering
What is a map?
• A symbolic picture of an area from up above
• It usually has a particular point of view, an
audience, and a specific purpose
The Map concept
• View from above
• Conveys information
• Represents SOME of
the features
• Those that are
navigationally useful
The Map concept
• Uses a symbolic
language
– Like Signs –
No Parking
– Like Sheet Music
Types of Maps
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Road Maps
Park Maps
Nautical
Aeronautical
Cave
Battlefield
Political
Geological
Topographical Maps
• x
Contours
• Horizontal Slices
through the earth
• Like a layer cake
• Shows the lay of
the land.
Contour Interval
Vertical Distance
between contour lines
Map Symbols
• USGS Maps
• Orienteering Maps
Map Symbols
• The symbols, Colors, and
shapes are the language
of mapping
• Mapping (Cartography) is
both a science and an art
– Science – uses agreed
upon conventions
– Art – allows for style,
emphasis, and general
differences in maps
Map Colors
• 5 Colors
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Yellow
Green
Brown
Blue
Black
• Plus the white of the
paper
• And a course overlay
in Red or Purple
White: Open Forest
Yellow: Open Land
Green: Thicker Vegetation
Brown: Shape of the Land
Contour lines represent
elevation in the
landscape.
Blue: Water Features
Black: Man-Made & Rock
Maping Symbols
Contours
• Common shapes
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Reentrant (v-shape, low ground, points up hill)
Spur (u-shape, high ground)
Ridge
Saddle )(
Knoll
• enclosed circle: top of a hill
• just a dot small hill
Orienteering Cincinnati, ©
2005
Contours
Re-entrant
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probably the most puzzling term encountered by the
beginning orienteer
kind of valley closed at one end
a re-entrant is an "entering" of the land into the hill
Orienteering Cincinnati, ©
2005
shallow
deep
Contours
Spur
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Is the opposite of a re-entrant
A projection or "nose" rising from the surrounding
ground.
Description
sheet symbol
Orienteering Cincinnati, ©
2005
Map symbols
Contours
Ridge
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The highest point running from knoll to knoll.
The best place to travel
Easiest running
Orienteering Cincinnati, ©
2005
Contours
Saddle
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The low point between two higher points..
Description
sheet symbol
Orienteering Cincinnati, ©
2005
Map symbol
Contours
Description
sheet symbol
Hills & knolls
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Dot knoll: A small obvious mound.
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Hill: an enclosed contour line.
Knoll
Hill
Both
Orienteering Cincinnati, ©
2005
Map symbols
Contours
• Telling up from down
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Closed circles are the tops of hills
Blue lines are steams and are at the bottom of hills.
Reentrants point up from streams to hilltops
Spurs point down from hill to streams and valleys
Orienteering Cincinnati, ©
2005
Contours
• Telling up from down
The re-entrant and the spurs are very similar.
Are they fat spurs and deep reentrants…
Or are they wide shallow reentrants with long skinny spurs?
Orienteering Cincinnati, ©
2005
Contours
• Telling up from down
You will unusually be able to find a stream and/or a knoll someplace
near on the map.
The streams are the lowest points.
The knolls are the highest.
Trace the highs and lows to the area of interest.
Orienteering Cincinnati, ©
2005
Parts of a map
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Title
Scale
Legend – key
Contour
interval
Map body
Compass rose
- N↑
Magnetic
north lines at
scaled
intervals
Additional information on map
• Location
– area map
• Mapping credits
• Update info &
printing dates
• Copyrights
• Contact info
• Access
permissions
• Logos
• Additional
boiler plate info
Overprint on map
• Course
• Description
sheet
Scale on Map
• Common USGS map scales
– 1:24000 1:62500 1:250000
• Common orienteering map
scales
– 1:15000 1:10000 1:5000
1:7500 1:4000
– Nominally called 1:15 1:10 1:5
Scale
• Compare 2 scales