Map, Compass & GPS

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

Tuesday, February 26, 2019

Caltopo Maps

Here is a good tutorial on how to use Caltopo and 


After reading about Caltopo and how awesome it was, I finally started to use it lately to plan trips and make my own maps.  Basically, you can make your own map and print it out using your own printer or maybe a really nice printer at work.  Additionally, you can export the map to various map apps on your phone, allowing you to have a GPS compatible map that shows where you are as you are hiking, just like a GPS unit.

Thursday, February 21, 2019

Magnetic Declination

Declination: A Noun. The horizontal angle between the true geographic North Pole and the magnetic North Pole, as figured from a specific point on the Earth.”

 Declination is a term that causes “brain cramps” for many of my students in my map and compass classes. When I mention Magnetic Declination eyes roll.

The web site has an excellent discussion of what declination is and what causes it:

“Magnetic declination varies both from place to place, and with the passage of time. As a traveler cruises the east coast of the United States, for example, the declination varies from 20 degrees west (in Maine) to zero (in Florida), to 10 degrees east (in Texas), ......the magnetic declination in a given area will change slowly over time, possibly as much as 2-25 degrees every hundred years or so.......... Complex fluid motion in the outer core of the Earth (the molten metallic region that lies from 2800 to 5000 km below the Earth's surface) causes the magnetic field to change slowly with time."

Land navigation is based on the relationship to the North Pole; also known as “true north.  The measure of degrees of direction in relation to true north is called “degrees true.”  Maps are laid out in degrees true.  Land features (buttes, mountains, streams) on a topographic map are in reference to degrees true.  By that I mean the bearing from one mountain peak to another will be referenced in degrees true.  The map below illustrates that point. 

Magnetic compasses do not point to true north (the North Pole); the magnetic needle points to an area that could be considered the magnetic North Pole. 
As illustrated below, declination data can be found in the diagram at the bottom of a USGS topographic map, (on some commercially produced maps it can be hard to find.) 

Because declination changes over time, I recommend that map declination information be verified at   This is essential in the Pacific Northwest where maps are notoriously out of date in terms of road,  and city data.
So, how do we make this simple?  How do we convert magnetic to degrees true?
I could do the math.  In Oregon, where I live, the magnetic declination is 15.6° East declination.

My recommendation: have the compass do the work so that there is no confusion with the math.

To do this, I need to choose a compass that can be adjusted for declination.  Some examples are the Silva Ranger or the Suunto M3.

With one of these compasses, the compass dial or housing is adjusted and rotated manually.  Both the Suunto and Silva Ranger come with a small, flat adjusting tool.  Consult with owner’s manual that came with the compass.

If declination is Easterly (Western U.S.) I will rotate the dial causing the baseplate’s orienting arrow to move in a clockwise direction.

   If declination is Westerly (Eastern U.S.) I will rotate the dial causing the baseplate’s orienting arrow to move in a counter-clockwise direction.

Now, adjust the dial and align the red magnetic needle on top of the orienting arrow (the red arrow engraved on the baseplate) the compass will provide directions in degrees true.

Food Toxic to Dogs

My wife and I have been doing quite a bit of traveling this summer.  In late May we visited our friends in Virginia.  We had a very long day of flying and looked forward to a relaxing visit.  While we were recuperating, the family’s dog was in the guest room scrounging through one of our suite cases.  My wife went to the guest room, found the dog and importantly, found a bag of Dove Dark Chocolate that had been opened with all the contents gone.  Out host called the local Vet Emergency room and was told to get the dog to the Vet ASAP.

On their arrival, the Vet administered a shot that quickly caused the dog to throw-up.  
The following are foods that are poisonous to our pets.  The Humane Society has a complete listing.

Chocolate, Coffee and Caffeine
Coconut and Coconut Oil
Grapes and Raisins
Macadamia Nuts
Milk and Dairy
Onions, Garlic, Chives
Raw/Undercooked Meat, Eggs and Bones
Salt and Salty Snack Foods
Yeast Dough

If you believe that your pet has ingested toxic foods contact the ASPCA Animal Poison Control Center at (888) 426-4435. 

Check the label information on the food product.  The Dove Chocolate packaging had a phone number on the back for emergency support.  I called that number and received excellent help.

Sunday, January 13, 2019

Trail Shoes

Section Hiker has a very nice review of Trail Shoes for the backcountry hiker.

Tuesday, January 8, 2019

Buying a New Compass

This is an older post but is a good reminder what to expect when shopping for a new compass.
Silva Ranger  - Outdoor Quest Image
There are several things to keep in mind when buying a compass.

My preferred compass is a declination adjustable sighting compass (with mirror) like the trail proven “Silva Ranger.” (Silva, Brunton and Suunto all make good compasses.) The key is that this type of compass can be adjusted for magnetic declination and that keeps your wilderness navigation simple. You can expect to pay roughly $35.00 - $60.00; a cheap compass will not serve the hiker well.

My experience is that most sales clerks are compass illiterate and have little navigation experience.  While looking at a compass ask the clerk to remove it from the plastic container/packaging.  Check the compass to ensure:
  1. The dial moves freely and does not stick.  
  2. There are no bubbles internal to the liquid filled compass housing.
  3.  Information engraved on the base plate must be legible.  If there is a magnifying glass verify that it is clear and not scratched. 
  4. The tick marks on the dial are in two degree increments.  The tick marks should be readable.
  5. The base plate, rotating dial assembly, and mirror are not chipped or broken.  
  6. The sighting assembly hinge allows freedom of movement without excess side to side movement at the hinge .
 Packaging should clearly state that the compass is declination adjustable.  Many adjustable compasses may have a small metal tool that allows for setting the declination.  If the packaging states that the compass has declination marking but does not use the word adjustable move to another model.

After purchase visit the website to determine the declination of the area the hiker will be traveling through.

Remember that the red magnetic needle will always point to magnetic north.  With a declination adjustable compass the rotating dial has been adjusted so that the information provided by the compass is now in degrees true.

Friday, December 28, 2018


Avalanche is of real concern for those who travel in the back country  during the winter.

A good resource  is the Pacific Northwest Avalanche Center.

Here is a link to their Web page:  Avalanche

Rattle Snake Bites

Take a look at the OUTDOOR magazine article by Kyle Dickman about snake bites. Bite