Transcript Basic Map and Compass Skills: How to Navigate in the Backcountry By Ken Stuber Fox Cities Backpackers Meetup Note: I shamelessly stole most of.

Basic Map and Compass Skills:
How to Navigate in the Backcountry
By Ken Stuber
Fox Cities Backpackers Meetup
Note: I shamelessly stole most of the graphics in this presentation from various websites.
I know that makes me a bad person… I’ve listed the various sites on the last slide.
I’m a geek, not a graphic artist. I actually LIKE clip art .
Maps
• Only useful for navigation if you know how to
use one 
• Several types
o Trail Maps: tend to show trails, trail
distances, intersections and main features,
but does not show topography (at least not
well, usually).
o USGS Maps: Designed for navigation, LOTS
of information crammed into a small space.
Can be difficult to read without practice.
o Specialty Maps: Often a hybrid of the above
two types, such as the “Trails Illustrated”
maps made by National Geographic. Great
for trip planning and basic navigation.
What to Look for When Choosing a Map
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Will you be travelling on-trail of off-trail?
How heavily used are the trails you will be on?
What is the terrain like?
In general, you’ll need a more detailed map if
– Trail is lightly traveled
– There is little relief, terrain is monotonous
– You will be off trail at all
• What scale?
– 7.5 min USGS maps 1:24,000. 1in = 2000ft
– “County” series USGS maps 1:100,000. 1in=1.6mi
Contour Lines
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Two dimensional representation of three dimensional space
Lines join points of equal elevation
Contour interval is the difference in elevation between lines
Every 5th contour line is an Index Contour which may have elevation marked on
it.
Reading Topography on a Map
• Shaded
Relief Map
1. Looks like a stylized aerial view
2. Shading gives depth, making it easy to tell mountain from
valley.
Reading Topography on a Map
• “Standard”
Topographical Map
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Summit – Concentric circles
Gentle Slope – Contours spaced far apart
Steep Slope – Contours spaced close together
Ridge – “Arrows” pointing down hill
Gulley – “Arrows” pointing up hill
Reading a USGS map
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Map Name
Year of Production and
Revision
General location in State
Next Adjacent Quadrangle
Map
Map Scale
Distance Scale
Contour Interval
Magnetic Declination
Latitude and Longitude
Reading USGS Map Features and Terrain
• Black - man-made features such as roads,
buildings, etc.
• Blue - water, lakes, rivers, streams, etc.
• Brown - contour lines
• Green - areas with substantial vegetation
(could be forest, scrub, etc.)
• White - areas with little or no vegetation;
white is also used to depict permanent
snowfields and glaciers
• Red - major highways; boundaries of
public land areas
• Purple - features added to the map since
the original survey. These features are
based on aerial photographs but have not
been checked on land.
Reading USGS Map Features and Terrain
Reading USGS Map Features and Terrain
Using a Compass
• Familiarize yourself with
the types of compasses,
their parts and features
• A quality compass will
have a movable
housing, scale and
orienting lines, orienting
and direction of travel
arrows, and declination
marks.
Using a compass without a map
• Find your intended direction of travel
on the compass housing
• Turn the housing so that direction
meets the Direction of Travel Arrow
• Hold the compass in your hand in
front of you, make sure it is perfectly
horizontal and away from metal
objects with direction of travel arrow
pointing ahead of you
• Rotate your body until the N-S arrow
on the housing lines up with the
magnetic needle
• The direction of travel arrow now
points in your intended direction
Using a compass with a map (step 1)
• Place the compass on the map so
that the edge connects where
you are with where you want to
be.
• The direction arrow on the
compass should point toward
where you want to be.
• You can also use the scale on the
compass at this time to measure
distance (as the crow flies)
Using a compass with a map (step 2)
• Hold the compass firm on
the map
• Turn the housing until the
North-South lines on the
map are parallel with the
orienting lines on the
housing
• Make sure the N-S arrow on
the housing is pointing
toward North on the map
Using a compass with a map (step 3)
• Hold the compass in your hand in
front of you, make sure it is
perfectly horizontal and away from
metal objects with direction of
travel arrow pointing ahead of you
• Rotate your body until the N-S
arrow on the housing lines up with
the magnetic needle
• The direction of travel arrow now
points in your intended direction
Traveling on the taken bearing
• Once you have your compass set for your
intended direction of travel (taken a bearing),
you need to get there.
• You can simply walk in the direction the arrow
points, frequently checking the compass
• Or find a feature in the landscape (Unique
tree? Rock? Ridge? Hill? Lake?) that lines up
with your intended direction. Walk there and
repeat.
Correcting for Lateral Drift
• It’s nearly impossible to walk a perfectly straight
line. Your error doing so is called Lateral Drift.
• One technique is to deliberately aim left or right
of your target, walk the expected distance, and
then turn toward your target in the direction you
intentionally missed. This way, you ALWAYS know
which direction you missed it by.
Navigating around obstacles
• When you reach an obstacle, hike a
rectangle around the object
– Set a new bearing 90° from your
original heading and walk until you
have cleared the obstacle. For
example, if your original bearing was
315°, hike a new bearing of 45°.
Count your paces to track distance
traveled.
– Go back onto your original bearing,
parallel to your original course until
you clear the obstacle along that axis.
– Set a bearing 90° back to your original
bearing (in this case 225°) and walk
the same number of paces.
– Now turn back to your original
bearing. You will be along your
original line of travel.
How do you use a Mirror Compass?
• Allows you to see the compass
dial and the background at the
same time
• Helps keep the compass level
while taking a bearing
• Can be bulkier and weigh
more…
Magnetic Declination
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Maps are oriented toward ‘true north’.
True North is the northern axis of the Earth’s rotation.
Compasses orient themselves toward ‘magnetic north’
Magnetic North is where the Earth’s magnetic field reenters the earth, the northern ‘pole’ of the Earth’s
natural magnetism.
• Magnetic North changes slowly over time, currently:
– Latitude:N 82° 17' 60"
– Longitude:W 113° 24' 0"
• Magnetic Declination is the measure of the difference
between true north and magnetic north, allowing us to
correct for it when navigating.
Magnetic vs True North
Magnetic North and True
North are not in the same
place, declination allows us
to correct for it.
Magnetic North
changes over time
So what does declination mean to us?
• You’ll need to find current declination for where you
will be
– http://www.ngdc.noaa.gov/geomagweb/#declination
• Then you need to adjust for it when taking a bearing
• You can do this one of two ways:
– Buy a compass with a settable declination screw
– Add or subtract the declination from the bearing
you took on the map
Manually adjusting for declination
• Rhymes and acronyms to help remember
– CEEC: Correct Easterly Errors Clockwise
– LARS: Left Add, Right Subtract
– East is Least(-), West is Best(+)
• With East Declination, subtract declination from map bearing to get
magnetic bearing
• With West Declination, add declination from map bearing to get
magnetic bearing.
• When going from magnetic bearing to map bearing, it’s the opposite!!
Sites I stole graphics from:
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http://www.usgs.gov/
http://www.exploringthenorth.com/porkiesum/map.html
http://www.princeton.edu/~oa/manual/mapcompass.shtml
http://www.walkandramble.co.uk/expert-advice/how-to-read-a-map-andcompass.html
http://www.enchantedlearning.com/geography/mapreading/topo/
http://en.wikipedia.org/wiki/Contour_line
http://www.spidercanyon.com/backiss/bimapnav4a.html
http://blog.backpackerbucks.com/gear/10-little-goodies-worth-jamming-in-abackpack/
http://adventure.howstuffworks.com/outdoor-activities/hiking/how-to-read-atopographic-map1.htm
http://www.learn-orienteering.org/
http://www.thecompassstore.com/
http://academic.brooklyn.cuny.edu/geology/leveson/core/linksa/magnetic.html