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.
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.
· 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.
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Map, Compass & GPS
Wild flowers along Fall Creek on the way to the Green Lakes - Oregon
Sunday, July 21, 2019
Navigating a Topograhic Map
Thursday, June 27, 2019
Hemlock - A Menace to Those in the Backcountry
This is post is all about a serious menace to folks in the backcountry. Hemlock is deadly.
Hemlock is a deadly invasive plant species that grows just about everywhere in the USA.
Noxious weeds are a real problem in Oregon.
My county has an aggressive program to get rid of these invasive weeds.
The image to the left is from a flyer that identifies the many weeds found in my region.
Hemlock is indeed a killer.
These plants are found along waterways and irrigation canals.
The mature poison hemlock -
"....is a biennial that grows 6 to 8 feet tall. Stems are erect, stout and purple spotted at all stages. Leaves on mature pants, as well as seedling plants, are fern-like in appearance. All plant parts are poisonous including the large white taproot. Humans ave been poisoned by mistaking the plant for parsley."
Note that the quote states that all plant parts are poisonous. I've talked to several ranchers who thought that only the taproot was dangerous.
Hemlock is a deadly invasive plant species that grows just about everywhere in the USA.
My county has an aggressive program to get rid of these invasive weeds.
The image to the left is from a flyer that identifies the many weeds found in my region.
Hemlock is indeed a killer.
These plants are found along waterways and irrigation canals.
The mature poison hemlock -
"....is a biennial that grows 6 to 8 feet tall. Stems are erect, stout and purple spotted at all stages. Leaves on mature pants, as well as seedling plants, are fern-like in appearance. All plant parts are poisonous including the large white taproot. Humans ave been poisoned by mistaking the plant for parsley."
Thursday, May 23, 2019
Snakes in the Backcountry
Are you ready for rattlesnakes? The following post is from a site that I just found a few years back. This is great info as you head into the backcountry.
On rare occasions, rattlesnakes can cause serious injury to humans. Most bites occur between the months of April and October when humans are most active outdoors. The California Poison Control Center notes that rattlesnakes account for more than 800 bites each year in the U.S. with one to two deaths.
What to do in the event of a snake bite:
Be Rattlesnake Safe
05/22/13 -- As warm weather returns, the California Department of Fish and Wildlife (CDFW) is reminding the public to be rattlesnake safe. All of California is snake country. Much like bats, rattlesnakes are often misunderstood. They play an important role in the ecosystem by keeping rodent populations under control.
California has six venomous snakes, all of which are various species of rattlesnake. They are heavy-bodied, blunt-tailed with triangular-shaped heads. A rattle may not always be present, as they are often lost through breakage and not developed on the young. Additional species information can be found here.
Rattlesnakes are generally not aggressive and usually strike when threatened or provoked. Given room, they will retreat and want to be left alone. They are not confined to rural areas and have been found in urban environments, lakeside parks and golf courses.
The best protection against unwelcome rattlesnakes in the yard is to have a “rattlesnake-proof” fence. The fence should either be solid or with mesh no larger than one-quarter inch. It should be at least 3 feet high with the bottom buried a few inches in the ground.
Keep the fence clear of vegetation and debris. Encourage and protect kingsnakes, which prey on rattlesnakes, and other natural competitors like gopher snakes and racers.
On rare occasions, rattlesnakes can cause serious injury to humans. Most bites occur between the months of April and October when humans are most active outdoors. The California Poison Control Center notes that rattlesnakes account for more than 800 bites each year in the U.S. with one to two deaths.
CDFW recommends the following outdoor safety precautions:
- Wear hiking boots and loose-fitting long pants.
- Never go barefoot or wear sandals when walking through wild areas.
- When hiking, stick to well-used trails.
- Avoid tall grass, weeds and heavy underbrush where snakes may hide during the day.
- Do not step or put your hands where you cannot see, and avoid wandering around in the dark.
- Step ON logs and rocks, never over them, and be especially careful when climbing rocks or gathering firewood.
- Remember, rattlesnakes can swim so never grab “sticks” or “branches” while swimming in lakes and rivers.
- Teach children to respect snakes and to leave them alone.
What to do in the event of a snake bite:
- Stay calm and wash the bite area gently with soap and water.
- Remove watches, rings, etc, which may constrict swelling.
- Immobilize the affected area and go to the nearest medical facility.
- DON’T apply a tourniquet.
- DON’T pack the bite area in ice.
- DON’T cut the wound with a knife or razor.
- DON’T use your mouth to suck out the venom.
- DON’T let the victim drink alcohol.
Tuesday, February 26, 2019
Caltopo Maps
Here is a good tutorial on how to use Caltopo and
Avenza.https://douchepacker.com/2016/04/28/quick-and-dirty-guide-to-making-a-map-in-caltopo/
Avenza.https://douchepacker.com/2016/04/28/quick-and-dirty-guide-to-making-a-map-in-caltopo/
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.”
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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 www.magnetic-declination.com 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 www.magnetic-declination.com. 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.
Alcohol
Avocado
Chocolate, Coffee and Caffeine
Citrus
Coconut and Coconut Oil
Grapes and Raisins
Macadamia Nuts
Milk and Dairy
Nuts
Onions, Garlic, Chives
Raw/Undercooked Meat, Eggs and Bones
Salt and Salty Snack Foods
Xylitol
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.