Map, Compass & GPS

Map, Compass & GPS
Wild flowers along Fall Creek on the way to the Green Lakes - Oregon

Thursday, November 15, 2018

Backstops for The Hiker and Hunter

A backstop keeps the hiker safe.  By using a natural and man made land features, a backstop keep the hiker in the right area.  Backstops are found by a careful study of a topographic map.

One feature every outdoorsman should pay attention to is called a “backstop.”   A  backstop is a boundary or a natural barrier that keeps one in their specified hiking area.  If a hiker goes beyond the backstop, then they will know they have gone too far.

When looking over a map of a hiking area, it is essential to understand the impact of terrain and land features.  Doing so will allow one to build an association of topography with a general lay of the land.  Key on natural and man-made features that includes roads, streams, buttes and buildings.  Take the time to really examine the map’s topography by studying the brown contour lines. This attention to detail will give the hiker a “feel” for elevation changes, shape and important land marks.  More importantly, it will allow the hiker to develop a mental map of the hiking area.  This concept lends itself to map training for those not backcountry experienced, and it is an excellent  teaching tool for children.



For example, in the image above ForestRd 32 serves as a backstop.  The hiker should remain west of ForestRd 32 because traveling east of 32 is hazardous due to the Swamp. Additionally, note that key terrain features associated with the trail include the river, mountains, a road and the swamp.

The example above is very simplistic but demonstrates the importance of having that “mental map”, especially if visibility becomes an issue.


The image above offers another example.

The map above is an area of steep terrain to the west, a lake to the east and trails surrounding most land features.  If the hiker planned to bushwack west of the campground (just below the larger lake) and hike in fairly flat terrain with gentle elevation changes, then the steep terrain to the west (Tam McArthur Rim) would be an excellent backstop. This is because it provides confirmation of the hiker’s general location. Care should be taken when using  trails that border Little Three Creek lake-note that the trail doesn’t continue west.  In such a situation, it is possible for the hiker to walk beyond the lake.

Backstops are another navigation tool that can keep the hiker in a safe location, and should be utilized as a visual resource.




Monday, November 12, 2018

Backcountry Travel Plann



After the loss of James Kim in the Oregon back country in 2006 I wrote a hiker's trip plan and posted it on my blog.  I had input from several valued sources.  I wanted something better for the wilderness traveler.  A plan more than a note to a neighbor.  My intent was to provide the search responders something valuable to go by.

In far too many SAR missions, the reporting party has little information for the searchers to go on to begin their search.

My plan can be found here.  It is a basic .pdf form.

Suggestions are certainly welcome.


911 Call center
Still, that responsible person plays a huge role in contacting authorities to begin a search.  My recommendation would be to pick a person that will make the 911 phone call without hesitation.

Travel safely.

Tuesday, November 6, 2018

The Essentials For Your Day Pack


Always Carry The Right Gear

On a warm afternoon in July, a family leaves a trail head with the goal of summiting the South Sister Mountain in Central Oregon.  It was a rough hike as they took a path not frequently traveled.  By evening it became obvious that this group would not make it to the summit and the glacier they were attempting to cross was icing up; it just wasn’t safe to press on.  911 was called and a local SAR team reached them after midnight.  The temperature on the glacier dropped below 40° (F) and the hikers were getting cold.

When the SAR team reached them, they found that the group had some food and water but no other gear.  The hikers’ clothing selection was questionable too.

So what is the right stuff to carry in the outdoors?  What is the minimum?  What should you consider before hitting the trail?

A climbing group in the 1930s, The Mountaineers from Seattle authored the “Ten Essentials” describing ten items that should be carried in the back country. 

“The Ten Essentials” has been modified by different groups over the years.  The following is the list that REI recommends:

  1. Navigation
  2. Sun protection
  3. Insulation (extra clothing)
  4. Illumination
  5. First-aid supplies
  6. Fire
  7. Repair kit and tools
  8. Nutrition (extra food)
  9. Hydration (extra water)
  10. Emergency shelter
    1. A space blanket is fine to carry but it is a poor shelter.

This is the minimum that one should carry; it is a starting point.  The key is to always carry your kit with you.  I have a day hiking kit that fits into a fanny pack.  It is only limited by its poor ability to carry extra clothing.


Thursday, November 1, 2018

Accurate Compass Readings

I found these recommendations a while back when I was researching techniques for using a magnetic compass.  A small error when using a compass can result in significant error in measurement on the ground.


To obtain accurate readings when using a compass:

  • Ensure the compass has been adjusted for declination. 
  • Hold the compass level and steady so the needle swings freely.
  • Hold the compass about waist high in front of the body, except when using a compass with a sighting mirror or a sighting type compass.
  • Raise and lower eyes when taking a bearing, do not move your head. Always use the same eye when taking bearings.
  • Directly face the object that is being measured.
  • Magnetic fields will give incorrect compass readings. Avoid taking readings near magnetic fields such as steel, iron (ferrous metals), vehicles, rebar, and clipboards. Even belt buckles, glasses, and rings can interfere with the compass reading.
  • Take bearings twice. 
  • Adjust for magnetic declination as appropriate.
  • Follow the direction of travel arrow, not the compass needle, when walking a bearing. Always follow the line indicated by the compass rather than relying on judgment as to the direction.
  • Use back bearings to ensure you are on track when navigating.
  • Compare compass reading with those of your GPS.
  • Remember that a GPS receiver's compass must be calibrated after every battery change.

Wednesday, October 31, 2018

More About Using a Topographic Map




Reviewing a topographic map is usually the starting point for the planning of any back country trip.  A topographic map is your road map to the outdoors.  It provides you detailed information at a scale that is meaningful and detailed.  For years, the US Geologic Survey (USGS) has been the principal publisher of accurate maps.  Within the last decade we have seen many innovations in mapping products that include new mapping companies and publishers, software, maps for the GPS, and “Apps” for the iPhone.
Outdoor Quest/Blake Miller image

Still, the USGS map remains the standard for back country navigation (visit the USGS’s site at www.topomaps.usgs.gov.)   I’d also recommend looking at June Fleming’s “Staying Found” or Bjorn Kjellstrom’s “Be Expert With Map & Compass.”  Once you develop a map foundation you will easily shift to many of the other products on the market today. 

Many publications, videos, and web sites will give you a te rundown on the features, symbols and components to a map.  This article will discuss a few of the key features that you should be aware on a 7.5 minute map.

·         Contour Lines These are the thin brown lines that snake across the map.  Contour lines connect equal points of elevation such that every point on that line will be at that elevation above sea level.  Visually, the contour lines give you a mental three dimensional view of the terrain.  These lines provide a view of slope and pitch, depressions, ridge lines and level ground; the highs and lows of the earth’s surface. 
Outdoor Quest/Blake Miller image
 These lines provide shape and a sense of texture. There are two primary types of lines, index and intermediate lines.  Index lines stand out as they are a touch wider, a darker shade of brown and indicate the elevation with numbers such as 4500; the elevation is in feet.  Between the index lines are the thin intermediate line that are spaced uniformly and further define the elevation, slope and contour.  The intervals between the intermediate lines are specified at the bottom of the map adjacent to the scale data.

·     Scale Consider scale as your view of the map; it is like your “overhead zoom” setting.  To cut to the chase, a 7.5 minute map or quadrangle has a scale that is referred to as 1:24,000; where one inch is equal to 2000 feet.  It is your best source of information of the back country.  At this scale, the map has much more validity and provides more usable information for your backcountry planning.  You can view important landmarks, streams and geographic features.  To complete the navigation picture I always refer a second map, such as a map of the national forest (e.g., the Deschutes National Forest.)  Commonly, such a map will be “zoomed” way out and have a scale of 1:100,000 or 1:250,000.  Imagine that such a map would be made up of many 7.5 minute quadrangles.

·    North  Features on a map such as trails, roads, mountain peaks and streams are all laid out in relation to true North; the North Pole.  The north-south borders of the map and the small declination diagram are your best references for true North.  Other grid lines (such as the red Township, Section and Range lines) may not be aligned to true north at all.  Be careful of these lines should you need to triangulate your position on a map.

·    Declination This is the angular difference between true North and Magnetic North.  The red needle on your magnetic compass points to Magnetic North.  The accuracy of the information found in the Declination Diagram is dependent on the age of the map.  To get the latest declination for any area visit www.magnetic-declination.com.

Personally I use a magnetic compass that I can adjust for declination; it just makes my navigation easier.  When adjusted, my compass provides bearing information in degrees true as does my map and my adjusted GPS.

·    Coordinates Latitude and Longitude (Lat/Long) are the familiar coordinate system to most outdoorsmen and women.  Coordinate data is found at the top and bottom corners of each map.  Lat/Long coordinate increments are also found every 2’ (minutes) and 30” (seconds) on the sides of the Map.  A scaling device is necessary to pull complete coordinates off a map; this is a pain.

In the 1940’s a coordinate system know as Universal Transverse Mercator (UTM) was developed.  To keep a very long story short, your 7.5 minute map has a new grid laid over it, the grid dimensions are 1000 meters by 1000 meters.  For more complete   information on UTM grid visit the USGS’s web site UTM or Lathem’s “GPS Made Easy” (which is probably at your local library.)

Simplicity is the essence of UTM.  Scouts, hunters and hikers have joined Search and Rescue (SAR) teams around the country in using this system. 

Your GPS receiver can easily be switched to UTM from the set-up menu.

·    Bar Scales   Notice the bar scales at the bottom of the 7.5 minute map.  The scales provide measuring data in miles, feet and meters.   On the far left side of the meter scale, the scale is broken down into units of 100 meters, this applies directly to UTM.

Notice on the scale bar (feet) that 1 inch equals 2000 feet.

·    Map Datum Information about map datum is found in the lower left corner of a 7.5 minute map.  I have found that the simplest definition from GPS maker Garmin is:

“A math model which depicts a part of the surface of the earth. Latitude and longitude lines on a paper map are referenced to a specific map datum. The map datum selected on a GPS receiver needs to match the datum listed on the corresponding paper map in order for position readings to match.”

The bottom line: most 7.5 minute maps are made to the North American datum of 1927 (NAD27 or NAD27 CONUS on your GPS).  New GPS receivers are set to datum WGS84.  The difference between the datum could be over 100 meters/yards.  The solution: When pulling points off a map shift your GPS’s datum to match the map. 

If precision is not an issue for your outing don’t worry about datum.

As you begin your trip planning don’t forget the magnetic compass, the important partner to any topographic map.  See Selecting a magnetic Compass for more information about buying a good compass.

Visit www.caltopo.com for free topographic maps of the Continental US.  This is a super mapping program that you can use to explore your area and print them at home.








Sunday, October 28, 2018

Free GPS Maps

There are several sources of Maps for your GPS receiver.

In the free category I like and use maps from www.GPSFileDepot.com. 

ONYXmaps.com maps are not free but the quality is just superb.  GARMIN has fine maps too but you will have to pay for them.

Do let me know if you have a free map source that are really good.

Thursday, October 25, 2018

Topo Map Bassics



Reviewing a topographic map is usually the starting point for the planning of any back country trip.  A topographic map is your road map to the outdoors.  It provides you information at a scale that is meaningful and detailed.  

For years, the US Geologic Survey (USGS) has been the principal publisher of accurate maps.  Within the last decade we have seen many innovations in mapping products that include new mapping companies and publishers, software, maps for the GPS, and “Apps” for the smart phone.


Still, the USGS map remains the standard for back country navigation (visit the USGS’s site at www.topomaps.usgs.gov.)   I’d also recommend looking at June Fleming’s “Staying Found” or Bjorn Kjellstrom’s “Be Expert With Map & Compass.”  Once you develop a map foundation you will easily shift to many of the other products on the market today. 

Many publications, videos, and web sites will give you a complete rundown on the features, symbols and components to a map.  The key features that you should be aware of are:


·         Contour Lines These are the thin brown lines that snake across the map.  Contour
lines connect equal points of elevation such that every point on a specific line will be at that elevation above sea level.  Visually, the contour lines give you a mental three dimensional view of the terrain.  These lines provide shape and a sense of texture.  Contour lines provide a view of slope and pitch, depressions, ridge lines and level ground; the highs and lows of the earth’s surface.  There are two primary types of lines, index and intermediate lines.  Index lines stand out as they are a touch wider, a darker shade of brown and indicate the elevation with numbers such as 4500; the elevation is in feet.  Between the index lines are the thin intermediate line that are spaced uniformly and further define the elevation, slope and contour.  The distance intervals between the intermediate lines are specified at the bottom of the map adjacent to the scale data.



·         Scale Consider scale as your view of the map; it is like your “overhead zoom” setting.  To cut to the chase, a 7.5 minute map or quadrangle has a scale that is referred to as 1:24,000; where one inch is equal to 2000 feet.  It is your best source of information of the back country.  At this scale, the map has much more validity and provides more usable information for your backcountry planning.  You can view important landmarks, streams and geographic features.  To complete the navigation picture I always refer a second map, such as a map of the national forest (e.g., the Deschutes National Forest.)  Commonly, such a map will be “zoomed” way out and have a scale of 1:100,000 or 1:250,000.  Imagine that such a map would be made up of many 7.5 minute quadrangles.


·         North  Features on a map such as trails, roads, mountain peaks and streams are all laid out in relation to true North; the North Pole.  The north-south borders of the map and the small declination diagram are your best references for true North.  Other grid lines (such as the red Township, Section and Range lines) may not be aligned to true north at all.  Be careful of these lines should you need to triangulate your position on a map.


·         Declination This is the angular difference between true North and Magnetic North.  The red needle on your magnetic compass points to Magnetic North.  The accuracy of the information found in the Declination Diagram is dependent on the age of the map.  To get the latest declination for any area visit www.magnetic-declination.com.

Personally I use a magnetic compass that I can adjust for declination; it just makes my navigation easier.  When adjusted, my compass provides bearing information in degrees true as does my map and my adjusted GPS.


·         Coordinates Latitude and Longitude (Lat/Long) are the familiar coordinate system to most outdoorsmen and women.  Coordinate data is found at the top and bottom corners of each map.  Lat/Long coordinate increments are also found every 2’ (minutes) and 30” (seconds) on the sides of the Map.  A scaling device is necessary to pull complete coordinates off a map; this is a pain.

In the 1940’s a coordinate system known as Universal Transverse Mercator (UTM) was developed.  To keep a very long story short, your 7.5 minute map has a new grid laid over it, the grid dimensions are 1000 meters by 1000 meters.  For more complete information on UTM grid visit the USGS’s web site UTM or Letham’s “GPS Made Easy” (which is probably at your local library.)


Simplicity is the essence of UTM.  Scouts, hunters and hikers have joined Search and Rescue (SAR) teams around the country in using this system. 

Your GPS receiver can easily be switched to UTM from the set-up menu.


·         Bar Scales   Notice the bar scales at the bottom of the 7.5 minute map.  The scales provide measuring data in miles, feet and meters.   On the far left side of the meter scale, the scale is broken down into units of 100 meters, this applies directly to UTM.

Notice on the scale bar (feet) that 1 inch equals 2000 feet.

 Map Datum Information about map datum is found in the lower left corner of a 7.5 minute map.  I have found that the simplest definition from GPS maker Garmin is:

“A math model which depicts a part of the surface of the earth. Latitude and longitude lines on a paper map are referenced to a specific map datum. The map datum selected on a GPS receiver needs to match the datum listed on the corresponding paper map in order for position readings to match.”


The bottom line: most 7.5 minute maps are made to the North American datum of 1927 (NAD27 or NAD27 CONUS on your GPS).  New GPS receivers are set to datum WGS84.  The difference between the datum could be over 100 meters/yards.  The solution: When pulling points off a map shift your GPS’s datum to match the map. 


If precision is not an issue for your outing don’t worry about datum.


Visit www.worldofteaching.com/powerpoints/geography/Mapping.ppt.  This power point presentation offers a fine overview of topographic mapping.  It’s free.