We’re stoked to be releasing two Travel Bugs into the Geocaching world. This is our first series of Travel Bugs and we hope you guys/gals will get involved with moving them through their missions.

If you’re not familiar with Geocaching or don’t know what travel bugs are please check out our Introduction to Geocaching article. Mike does a great job of giving you the basics about getting started. If you are a seasoned Geocacher then you know how much fun it can be to help travel bugs along their way.

Both Travel Bugs will be launched from the UDT/SEAL Museum in Ft Pierce Florida. We started a cache named In Memory Of Our Fallen (GC37M7X ), which is right outside the entrance to the Museum and also the inscription on the ITS Tactical brick at the UDT/SEAL Museum.

 We have included some cool swag to start the cache off right and the photo above is of the actual container you’ll find. While we have a few ITS related items, we definitely don’t want this to come across as “commercial” in any way. There are very specific rules about not commercializing caches.

As seen in the photo we have included things for kids to trade and this really that is what Geocaching is all about. Getting out there with your family and spending time outside doing something fun. So hit the trails with your friends and family and enjoy Geocaching. If you come across one of our Travel Bugs make sure to let us know. We want to hear your story!

Mission #1

The first Travel Bug’s (TB48NJ4) mission is to get to the beach at Coronado in San Diego California. There is a cache named Double Bubble Trouble (GC1BR4C) which should provide views of the SEAL training area. It would be great to see some photos of the TB near the obstacle course!

Mission #2

This Travel Bug’s ( TB48NJ6 ) mission is to travel to the Virginia beach area.  The cache is named Redwing (GCHTEZ) which is near Dam Neck road. While not near the beach this should be a cool spot to end this journey as there is a POW Memorial at the park. It would be great to get a photo of the TB at the memorial.

UDT/SEAL Museum

If you ever get a chance to visit the Museum make sure go. Let them know ITS Tactical sent you and ask where our memorial brick is located. They do an excellent job of showing the history of the Under Water Demolition Teams and current Navy SEALs.

The sacrifice and courage that these young men undertook in the early days of the UDTs and still to this day will make you proud to be an American. All that’s needed to see what our current SEALs are able to achieve, is to walk around the Maersk Alabama’s lifeboat. You can’t truly grasp the perfect shots these snipers took until you see it for yourself.

Please let us know if you have any questions or comments below!

With our legs screaming, our breathing fast and shallow, we continue climbing. The GPS says we’re just a few hundred feet away and while we tried to resist bushwhacking due to the waste of energy, if this gamble pays off it will net us a solid 40 points. The second most valuable checkpoint in the race.

My brother and his wife have joined me in the second ever Gear Junkie Treasure Hunt taking place in Roanoke, Virginia. It’s quite a drive from Washington, DC but it sure is scenic this time of year and the weather was absolutely perfect.

2nd Annual Gear Junkie Treasure Hunt

The Treasure Hunt is most similar to a beginner adventure race. There were 25 hidden flags with special pin punches for your ‘passport’ to prove their discovery. Also, this year they included a bit of trivia for some checkpoints in addition to the punches.

photo © Gear Junkie

You’re only allowed three hours to grab as many checkpoints as possible and whoever gets the most has the pleasure of entering the gear tent first and so on down the line. It pays to be fast. We came in tied for 29th place out of 120 entrants.

photo © Gear Junkie

There was an incredible amount of gear this year totaling over $40,000. Some of the high end items included a Specialized Carve Pro 29′er mountain bike, Raleigh Revenio 3.0 road bike, Necky Rip 12 kayak, at least 5 handheld GPS units from Delorme and Magellan, and Benchmade Griptilian knives.

While officially there are no teams because you can’t combine points, I recommend going with friends and family for a more enjoyable experience. My brother and I seem to get on the same wavelength and once we ‘sync up’ we operate like a well oiled machine. The miles melted away as we snagged more and more checkpoints.

photo © Gear Junkie

At the end of the day we covered 10.6 miles in just under 3 hours. The terrain included city streets, hiking trails and everything in between. Nestled among nearby rolling hills and the rising Blue Ridge Mountains, Roanoke is an ideal location for a scenic romp through the Fall foliage.

[view interactive map]

Next time I’d like to try one of those adventure racing map pouches that hang around your neck. Having the map hands free and protected from sweat and dirt would be nice.

If you’re in the area, keep a lookout for the next Treasure Hunt (the first one was last summer). It’s a great way to spend the weekend; getting some exercise and free gear!

Load Out

• Garmin E-Trex 20
• GORUCK GR1
• Source Hydration 3L Bladder (filled halfway for weight)
• ITS Tactical Liberty Bottle (it’s new and I wanted to beat it up)
• REI Endeavor Convertible Pants
• Under Armour Compression Shirt
• Outdoor Research Sequence long sleeve zip tee
• Outdoor Research Helix windbreaker (won at last years Treasure Hunt)
• GU Energy Gel

Bonus

This year, the event coincided with the first annual Outdoor Circus featuring dozens of vendors including Specialized, Trek, Raleigh, trials riding demos from Giant rider Jeff Lenosky, live music, local bike maker Six Eleven Bicycle Company and enough concessions to keep you fat and happy.

The ‘Circus’ provided us with some much needed rest and relaxation after the race while we waited for the rest of the heats to finish. They also allowed people to camp out in tents and if they do this again next year, I’ll be sure to setup camp!

Geocaching Ready - circa 2004

Most of you are probably familiar with Geocaching (pronounced ‘geo-cashing’) one way or another. In it’s simplest form, Geocaching is a ‘treasure hunt’ where users with GPS devices find hidden containers (called caches) and log their visit.

Sometimes there are even items in the caches to trade. It’s honestly just a great excuse to get off the couch and explore the great outdoors.

My Geocaching ‘career’ started in high school. I picked up a Garmin Geko 101 from Radio Shack and while it was super entry level and didn’t have any bells or whistles, it did everything you need it to do for Geocaching; Just input the GPS coordinates and go!

Now I use my iPhone as my primary Geocaching tool. I can search for caches based on my location, find and photograph them, and log my visit all from that one device. The official app only costs $10 and is a great way to get introduced to the hobby. If you get serious about it, you may want to add a better GPS device to your kit.

Caches range from the super easy where you just drive up in you car, to the all day multiple caches that require you finding them in order and frequently involve stream crossings and rough terrain.

Getting Started

• Make an account on Geocaching.com
• Buy or borrow a handheld GPS or purchase the iPhone app.
• Find caches nearby and go!

It’s really that easy!

What to Bring With You

• Pen or pencil
  • For logging your visit or taking notes. Not all caches have a writing tool with them.
• Scrap paper or notebook
  • A cache may be flooded so you can replace the log with a new one or you may just want to leave a message.
• Flashlight
  • Even though it may be sunny, you might need to search dark spaces.
• Multi-tool or small tool kit
  • You’d be surprised at how many times a set of long tweezers has come in handy.
• Any collectibles to exchange
  • If you take something from the cache, be sure to leave something of equal or greater value.
• Bug spray
• Camera
• Notes of the cache you are hunting for.
  • You can print them from the site before you go out. Some cachers keep a 3 ring binder to organize the caches and notes.

Types of Caches

There are over 10 types of caches but the most common are the ‘traditional.’ The coordinates usually point to the exact location and they are either easy to find or involve just a little searching (no trivia).

• Traditional
• Multi-cache
• Mystery/Puzzle
• Letterbox Hybrid
• Locationless/Reverse
• Moving/Travelling
• Virtual
• Earthcache
• Webcam
• Event Cache
• Wherigo Cache

Terminology

There is practically a whole library of slang and abbreviations for Geocaching but here are the most common. Some of these may be posted on your log/report online or even on the cache notes itself.

• Muggle – Non geocacher
• BYOP – Bring your own pen/pencil (cache is too small to store one)
• DNF – Did not find.
• FTF – First to find
• TFTC – Thanks for the cache
• TN / LN / SL – Took Nothing, Left Nothing, Signed Log

Mindset

When I started Geocaching, I noticed something changing. I was looking at things differently, often wondering if it would make a good hiding place. While you usually have the coordinates for the cache, it’s not always in that exact spot. You have to start changing your mindset.

I’m not the only one that now sees things differently because of Geocaching though. Sergeant Kent “Doc” Byrd, a member of an EOD unit in the Army, says his skills in Geocaching help keep him safe while on duty.

Oh and if you’re feeling particularly adventurous… you’ll notice that some caches are much harder to reach than others. Like the one you’ll need to SCUBA dive to or the one on the International Space Station. Good luck!

Are you a Geocacher already? If so, friend us up here on Geocaching.com! You have to have an account to view that page or you can search for us under the username ‘ITS Tactical‘. Happy hunting!

The LandNav series has reached its zenith; we’re now at the point where we are ready to learn how to use the map and compass together to maneuver.

In one sense, maneuvering with the map and compass is rather elementary since the compass is effectively employed as a protractor and ruler.

The straight sides of the compass’ base plate are used as a ruler to connect points and measure distances. This, in fact, is the first step in maneuvering from point A to point B with the map and compass.

Putting it Together

Step 1: Use the compass edge (or ruler) to draw a line from your starting point to your destination.

The 360° represented by the compass bezel serves as a protractor. We use this protractor, in conjunction with the arrows on the base plate to obtain a heading that needs to be traveled to reach the destination.

Step 2: With the direction-of-travel arrow pointing to the destination, turn the compass bezel until the orienting arrows are pointing north and aligned parallel with the nearest north-south meridian.In the photo below, an exaggerated north-south line has been added- look closely and you can see the light pencil lines used in practice.

Often the map will not include the north-south lines in the map body. Using a straight edge aligned with the map border, you only need to draw one north-south line that is within the bezel of your compass so that you can effectively obtain the heading.

The key prerequisites for step #2 include orienting your map and accounting for declination—both of which were covered in previous articles in the series. Once the compass’ orienting arrows are both pointing north and aligned parallel with the nearest north-south meridian, read the heading from the bezel at the little white triangle between the two red orienting arrows. This is the heading, or azimuth, that you’d need to travel from the origin to reach the destination.

Warning: Ensure that your compass is pointing from the start to the destination. If you place your compass at your destination and point backwards, your readings will be opposite what they should, and you’ll actually travel away from your destination!

Azimuth

Formally, an azimuth is defined as a horizontal angle measured clockwise from a north base line. A back azimuth is always 180° away from the azimuth, and it is how you “find your way home” back to your starting point. If you azimuth is 180° or less, then you always add 180° for your back azimuth; otherwise subtract 180°. For example, if your azimuth was 74°, then your back azimuth would be (74 + 180), 254°. In contrast, if you azimuth was 337°, then your back azimuth would be (337 – 180), 157°.

If you need to estimate the distance between the two points, one inch on a 1:24,000 scale map is 2,000 feet. Measure the inches between the two points, then multiply by 2,000 to get the distance. Alternatively, the scale at the bottom margin of the topo map can be used to obtain the distance using other units of measure, e.g. meters.

Often the distance is greater than the length of the compass base plate. A common way to measure distance, especially if there are obstacles in the way that must be navigated, is to use the lanyard on the compass. The string is extremely malleable, and easy to create 90° turns.

Practical

Let’s put this into a practical exercise. Say that we are interested in visiting cemeteries to read the old headstones. We are presently at Bethel Church Cemetery (4955/9420), and we want to shoot an azimuth to our next cemetery, Allen Cemetery (5250/9510).

After drawing our line, we get our heading of 74°. At the cemetery, we hold the compass flat, extended slightly out from our chest and turn our body until the compass needle is “boxed” inside of the orienting arrow. Wearing a huge metal belt buckle, or if your pack has a lot of metal on it, you may wish to remove that gear so that you obtain an accurate heading. Look up on the horizon and try to find a distant landmark to aim towards. This can be more difficult in flat terrain. Proceed to walk in that direction toward your destination.

Before we set off, we look over the path and realize that our heading has us going straight through a small body of water—unacceptable! What we will have to do is maneuver around the obstacle. We can do this by choosing a 90° heading off of our original azimuth for a fixed distance, get around the width obstacle, then continue parallel to our original azimuth until we are past the length of the obstacle. Once past the obstacle, we turn back 90° until we join our original track line—turning 90° once more, then continuing on our original track. For illustrative purposes, I choose the southerly route (a greater distance, but equally effective) around the pond (see photo above).

Pace Count

In the field, the most effective way to measure around small obstacles like this pond is to measure your distance by counting your stride, known as a pace count or tally count. Even if you have no idea just how much ground you cover between paces, so long as you accurately count your paces out, then match that pace count back after making your turns—you’ll end up on the same track line from where you started out.

Formally, one step is the distance one covers when measured from one foot to the other foot. A stride, in contrast, is the distance between two steps. Stated differently, a stride is the distance between where the left foot strikes the ground and the next time that the left foot strikes the ground. The measure of your stride is known as a pace or tally.

One thing to consider is that your pace will vary based on many factors- going up hill versus down hill, morning treks versus late afternoon treks where you’re tired from spending the day on the trail, etc. No easy solutions exist to these problems; spending time on the trail and practicing will help you refine your ability to estimate distance covered.

Keeping a tally count doesn’t involve high-tech solutions. Common trail approaches include grabbing a string and tying a knot every 100 strides, or grabbing a handful of pebbles and moving a pebble from the left pocket to the right pocket every 100 strides.

More information about how to calculate your pace count can be found in this ITS article from the archives.

Waypoints

On longer treks, the journey will often include waypoints. A waypoint is an intermediate destination. For example, if the pond was actually a respectably sized lake, and our journey was planned for 3 days, we would break up the journey into waypoints. The first waypoint might represent where we are stopping for lunch, with the next waypoint representing where we’ll have dinner and setup camp for the evening.

Rarely is an overall trek in the backcountry as simple as navigating from point A to point B, yet in practice every piece of the journey is just that simple. Today, the marvel of handheld GPS devices makes backcountry navigation simpler, but not foolproof. Batteries die, devices are lost, dropped in the river, etc. Having the skill to resort to a compass and map is critical on a backcountry adventure. Unfortunately, this skill is highly perishable—so get out in the backcountry, leave your GPS in your pack, and practice navigating the old fashioned way with a map and compass!

In its essence, the Universal Transverse Mercator (UTM) system divides up the globe into small, manageable segments. Rarely is someone going to set out and hike from Oregon to Maine and most planned adventures, even when spending a week in the backcountry, won’t require more than a handful of quads.

Latitude and longitude is obviously a very valid way of referencing your position on the globe, but most recreational outdoorsmen have moved on to UTM. Likewise, the military uses MGRS, another type of globe grid system, in lieu of latitude and longitude. MGRS is a topic which will be covered in-depth in the future.

Dividing the World

UTM divides the world into 60 north-south zones, each 6° wide in longitude. The zones are numbered consecutively, Zone 1 through Zone 60. Based on this width, the entire US is represented with just 10 zones, Zone 10 on the west coast through Zone 19 on the east coast.

UTM coordinates are two-dimensional and they are referred to as an easting and a northing. Northing values originate at the equator and count up from zero as one heads north. Heading south, the equator is assigned an arbitrary northing value of 10,000,000 meters—simply to avoid negative numbers when heading south of the equator.

Northing numbers are found on a map’s left and right margins, Easting values are found on the map’s top and bottom margins. Easting values originate from a central meridian drawn through the middle of each zone; they are assigned the value of 500,000. Any location west of this meridian is a value less than 500,000; east has a value greater than 500,000.

All USGS 7.5-minute quadrangle maps, 1:24,000 scale, include UTM ticks around the map margin. The tick lines are indicated at intervals of 1,000 meters, typically using the color blue. The full UTM meter value is displayed for the ticks nearest the southeast and northwest corners of the map.

Referencing the Huntsville quad’s northwest corner, we can see a northing value of ³⁴04⁰⁰⁰ meters, and an easting value of ²49⁰⁰⁰ meters. Based on the easting, we can tell that we are west of the Zone 15 meridian because we are counting up towards 500,000 meters.

The rest of the map uses only 4 digits to represent the UTM location. The first 2 superscript numbers in the northing, for example 34, represent the 1,000,000 and 100,000-meter grids. The last two numbers represent the 10,000 and 1,000-meter grids. Therefore, ³⁴04 on our quad means 3,404,000 meters north of the equator.

Plotting

Navigating against the UTM grid requires an interpolator, commonly known as a plotter. My personal preference is either the MadAthelete.com UTM plotter, available at Amazon.com for the meager price of $7.50, or this Grid Scale Reader, which is marginally larger. The purpose of the interpolator is to allow you to easily break the 1,000-meter grid down into 100-meter chunks.

UTM coordinates are always presented Easting/Northing. In other words, we form our UTM coordinates by starting from the left hand side of the map, working right, then moving upward from the bottom of the map to the point of interest. The common phrase to remember is read-right-up. Now, let’s see this in practice.

We want to rendezvous at the Bethel Church Cemetery so we can jump on the nearby hiking trail. Starting at the left side of the map, we navigate towards the east to the cemetery. Using a straight edge, we can mark the closest easting position—in this case ²49. We move the interpolator into position moving from the left side of the map towards the east as well. The result is a reading of 49550.

Next, we repeat the process to retrieve the northing value. Using a straight edge, we mark a horizontal line from which we can measure the northing—the closest northing is ³³94. We slide the interpolator up, obtaining the reading of 94200.  We would give the UTM grid as 4955/9420. Collectively, the 8-digits of accuracy represent a point to within 100 square meters, a measurement that is usually more than adequate for most land navigation requirements. The photo shows how the interpolator helped me determine the granular reading.

You’ll notice that the easting/northing reading usually omits the superscript values. If you are passing these coordinates to recipients who may not have any idea where on the globe you are, you would want to give them a full reading that includes the zone and 10-digits, something like, “Zone 14, 49550 94200.” The 10-digit reading describes a point to within 1 meter.

Magnetic Declination

Knowing that we like to go off-trail, we decide grab our map and trusty compass for the trek. The first thing we need to do to prepare for our hike is to lookup the declination for the area. Using the app on my iPhone that we setup previously, I punch in the zip code of the area I’m heading to (because I know it off the top of my head, and I don’t know the lat/long off the top of my head). NOAA reports that the declination is 3° 21’ E, changing by 0° 7’ W per year . Armed with this data, I set out to update my compass.

My personal preference is the Suunto M3; it includes a mechanical declination adjustment capability. Flipping over my compass, I adjust it from its default setting of 0° to approximately 3° E. The compass helps take the guess work out of which way to turn, labeling one side “E Decl” and the other side “W Decl” for me. Gently, I turn the gears so that I line up as reasonably close as I can to 3° 21’ E. Now, I can make my heading calculations on the map using the default grid lines of true north, yet know that when I shoot an azimuth with my compass in the field I’ll be heading the correct direction.

Orientation

Once I get out to the cemetery, I need to orient my map.  I do this by following a couple of steps:

1. Lay out my map on a flat surface, not the hood of your truck! Remember, your compass doesn’t behave well around large metals objects!
2. I turn my declination-adjusted compass bezel to due North.
3. Find an adequate reference line, lining up the orienting lines—the red parallel lines running in the middle of the bezel—with north-south meridians on the map. On your map it should be easy to notice how the direction of travel arrows are all parallel with the meridian lines or ticks—it is difficult to see that in my photo due to the photographic angle.
4. Finally, turn both the map and the compass together until the compass needle is “boxed” inside of the orienting arrow. Some people refer to this as red in the shed.

It’s worth nothing at this point one of the subtle challenges of using the Brunton 8096-AR compass that I pointed out in last weeks compass selection article. That compass lacks the orienting lines, making this process much more challenging than it need be.

At this point, we are ready to mark our starting location on the map, and begin the decision process of figuring out where to go on our hike. That’s where we’ll pick up next time, as we talk about shooting azimuths, identifying waypoints, tally counting, and more.

Notes

For the truly motivated, the LandNav series uses the Sam Houston National Forest as the training grounds for most of our cartographic adventures. If you’d like to download a PDF of the topo map we’re using to follow along, it’s the Huntsville 7.5 x 7.5 1997 map. It has an alternate ID of TTX1823, ISBN 978-0-607-93473-1. A printed version can be purchased from the USGS Store for $8.

Today we are going to continue from our last article on Reading and Associating Terrain and discuss compass selection for use in land navigation.

Compass selection is often driven by personal preference, much like some prefer one vehicle make and model to another.

Our goal with this article is not to suggest which compass to buy before you know how to use it, but rather to show you the different options out there. We feel it’s important and necessary to have a compass at your disposal during this series.

Categories

Many manufacturers will often group their compasses into three categories: professional, sports, and recreational. In reality, there are effectively only two broad categories of compass types: clear base plate models used for orienteering and lensatic compass, effective for distance sighting with mirrors.

Virtually every book and instructor will go out of its way to point out that in experienced hands, either type of compass can be highly effective—a point worth emphasizing here. As this series is about getting back to basics, we aren’t going to cover the plethora of digital compass solutions that have shown up in the market over the last half-dozen years.

Why? Because batteries fail and you should always have a “manual” compass with you anytime you are relying on a digital one, including GPS!

Manufacturers and Features

Three of the dominant compass manufacturers include Suunto, Brunton and Silva. Between the three of them, there are about 40 different compass models to pick from, each with a different combination of features.

Let’s take a look at the features available on compasses and what you should look for in the compass you choose to purchase.

Base Plate

A no frills base plate compass, like the Brunton 7DNL ($15.00 list) or the Silva Starter 1-2-3 (list $9.99), are simple compasses that provide the navigator with the basic essentials and no more.

These essentials include an orienting arrow with orienting lines, a degree dial bezel at 2° graduations, and usually one or more scales or rulers along the edges of the compass.

In contrast to these base plate models, middle-tier models like the Silva Explorer Pro (list $27.99) provide additional features that simplify land navigation tasks. For example, on long journeys at certain latitudes forgetting about magnetic variation (declination) can be very costly.

The basic models provide a declination scale, but lack the ability to physically adjust the compass so that it operates at a given declination. The Explorer Pro is a compass that provides a gear driven adjustment mechanism. If you’re going to purchase a new compass, this is a highly recommended feature.

Global

Further up the price tree are base plate models like the Suunto M-3 Global (retail $42 @ Amazon.com). This compass includes anti-slip rubber pads, a magnifying lens, and luminous markings for those occasions where you’re moving at night.

One unique marketing feature that Suunto promotes is that many of their compasses operate against two geographical balancing zones. These balancing zones are important because the vertical intensity and direction of the earth’s magnetic field fluctuates as you move around the globe.

Ensuring your compass is properly balanced for the part of the world you are going to use it in cannot be an afterthought. In Suunto’s case, they have balanced most of their product offerings for two zones, instead of the five zones that the globe is typically sliced into. If you don’t plan on heading over the equator, you’ll only need to purchase a compass balanced for the northern hemisphere.

Adventure Racing

Brunton offers the 8096-AR, a compass marketed explicitly toward adventure racers. The base plate includes a latitude, longitude and UTM template for critical details, but it lacks in two areas. I speak from first-hand experience.

The 8096 compass was intentionally designed without orienting lines, and the circle-over-circle alignment system isn’t very user friendly. Judging if the circles are properly aligned can lead to a 2° to 4° degree variation.  That makes a HUGE difference on long waypoint hikes.

The bottom line: unless you are using this compass to compliment a GPS, taking advantage of GPS features (like the five confidence circles along the edge) this compass is outright hard to use with a map. Keep this in mind if this compass makes your short list.

Lensatic

The lensatic compass differs from the base plate model in many ways. First, instead of a clear and rigid plastic base, the lensatic compass has articulating pieces, including a cover that protects the floating dial.

Second, the lensatic compass comes with a sighting mechanism for navigating across great distances by shooting headings at distant landmarks. Shooting headings is possible with a base plate, but the lensatic allows the user to line up very specific targets using its sighting lens.

Most base plate compasses provide 2° increments on their dial, while lensatic compasses contain 120 clicks when rotated fully; each click represents a 3° shift. Instead of looking down directly at the floating dial, the user relies on the lens to read the dial.

Recommendations

Admittedly, it has been years since I’ve worn a uniform and used a lensatic compass like I was trained on back in the day. My transition to civilian life included switching over to a base plate compass.

My personal preference in a compass is a simple base plate model, complimented with the MadAthelete.com UTM plotter, available at Amazon.com for the meager price of $7.50. This plotter is the size of a credit card and convenient to carry. If you’re still using MGRS as your primary navigation means, check out the MGRS/UTM Coordinate Grid Reader & Protractor instead for $6.95.

To reiterate an important point from the introduction, either compass in experienced hands will get results. The key to this sentence is experienced hands.

Notes

If you’re confused on some of the features we’ve described, we’ll be getting into how to properly use them in a future article in this series. Each of the articles in the LandNav101 series are building blocks and are to remind each of us that land navigation is a perishable skill. Learning to use a compass and then letting it collect dust for 5 years does not equate to experienced hands regardless of the compass category.

Next week we are going to formally introduce the UTM grid. We’ll be using our topo map for Sam Houston National Forest, a base plate compass with orienting lines, and the handy UTM plotter.

The LandNav 101 series is using the Sam Houston National Forest as the training grounds for most of its cartographic adventures. If you’d like to download a PDF of the referenced topo map, it is the Huntsville 7.5 x 7.5 1997 map. It has an alternate ID of TTX1823, ISBN 978-0-607-93473-1. A printed version can be purchased from the USGS Store for $8.

Today we’re going to discuss how to read terrain off of a map. Reading terrain is more about artistic visualization than it is science. There are three major factors that aid in the visualization of terrain from a 2d map:

• Contour Lines
• Colors
• Shading

The ability to fuse these major factors is the most critical skill one can learn when using a topographic map. The primary purpose of a topographic map is to accurately represent the shape of the Earth’s surface, but the utility doesn’t stop there. Topographic maps also represent streets and trails, vegetation, streams, and every type of feature that may positively or negatively impact your ability to navigate through the terrain.

Contour Lines

Contour lines are imaginary; they are map artifacts used to represent paths or segments of Earth at an equal elevation. These paths and segments are presented as elevations (vertical distance above or below sea level) and reliefs (the shape of terrain features on the Earth’s surface).

Not all contour lines are created equal. Heavier contour lines are known as indexed contour lines and are normally numbered showing elevation. Typically every fifth contour line is an index.

Lighter contour lines, that fall between indexed lines, are known as intermediate contour lines. These lines do not have their elevation given and are found in sets of four between indexed contour lines. Finally, when the terrain is expansively flat, cartographers will often include supplementary contour lines, which are dashed lines indicating an elevation that is half of the elevation between the contour lines surrounding it. They are typically found where there is little change in elevation.

The key thing to remember about contour lines is this: The closer the spacing, the more rapid the change in elevation. For a leisurely Sunday stroll, you might be looking to cross just a few contour lines, or perhaps follow a trail that shadows a few contour lines on the map. For rock climbing, look for a concentration of contour lines in a single area. If you’re looking for a true vertical cliff, look for a series of contour lines drawn so closely together that they appear to be a single line.

The Huntsville quad doesn’t really have any hard elevation terrain (though navigating swamps can be pretty hard). Notice the foot trail along the top image. It intersects two indexed contour lines, but the distance between the indexed contours is pretty significant; it’s easy to see that this is a very easy path to navigate with respect to elevation gain.

In contrast, the bottom graphic shows a hill where the top is at 438’. The indexed contour line to the immediate left if 400’, and the one further left is 350’. Walking up the western face of this hill would be more challenging than traversing the easy foot trail.

Topographic Map Colors

As you can imagine, there’s an entirely different survival mindset for each environment. For example, surviving in the mountains above 10,000 feet in October is radically different than surviving in the desert in July. This is why it’s important to know the terrain you’re traveling into and what the map of that area is telling you.

The color brown is used to denote most contour lines on a map, which are relief features and elevations. Topographic maps use green to denote vegetation such as woods, while blue is used to denote water features like lakes, swamps, rivers and drainage.

At higher elevations, mountains may be snow-capped year around, or the terrain may actually be a glacier. In each of these cases, contour lines are also drawn in blue. It is therefore possible to quickly discern that a particular route from A to B might be more treacherous than operating at a high altitude—the trek might require crampons, an ice axe, and other materials that might not be readily available once in the backcountry.

Finally, black is used to represent man-made objects, including trails. Red is used for man-made features, like main roads or political boundaries, and purple for new changes or updates on the map that weren’t previously represented. Newer maps no longer use purple, but since so many older maps exist, it’s worth mentioning.

At the bottom of the Huntsville quad is Lake Raven shaded in blue, since it’s a water feature. Notice the thick red line, delineating a political feature, the state park boundary. The majority of the image is shaded green, showing that this part of the map is full of vegetation. Contour lines are present in brown, as are two different types of paths: an unimproved or 4 wheel drive trail represented by parallel dashed lines and a foot trail represented with a single dashed line.

Admittedly outside of our topographic scope, it’s worth noting that the USGS also provides extensive documentation on colors (and shading) for representing geologic features. This could be particularly useful for those interested in either rock climbing or geology in general. See the USGS Colors and Patterns for Geologic Maps for more details. If I ever get the opportunity to spend a couple weeks in southern Utah, I intend on bringing along a geologic map in addition to my topographic map because I enjoy knowing that I’m looking at rock that dates back to the Jurassic or Cretaceous period.

Shading

Color similarity between features does not mean that the features are equivalent. Due north of Lake Raven is the Prairie Branch, another name for a stream. Other names that equate to a stream include kill, run, fork, and brook. What’s interesting about Prairie Branch is that has led to the formation of a wooded marsh or swamp.

Navigating across Prairie Branch could be difficult. Since this is Texas, expect to run into water moccasins, copperheads and perhaps the occasional alligator among all of the other friendly animals that call Sam Houston National Forest home.

Remembering map colors is a fairly trivial task, but remembering the shadings is far more difficult given the sheer number of variations. For this reason, keeping the USGS Topographic Map Symbols, a mere two sheets of paper, behind your map can be a lifesaver. A quick reference to page four of the booklet confirms that Prairie Branch is indeed a submerged wooded marsh or swamp.

Terrain Association

Orienting the map is an exercise that rotates the map so that north on the map is aligned with north in the real world. Orienting a map is critical because it allows you to point in a direction and know with confidence what terrain lies ahead. But if your compass breaks, how will you know where you’re headed?

It happens! You may find yourself in the backcountry with a map, but that fall (more like a slide) down that last rock face shattered your compass. Now what? Well, the key is to read the terrain and orient your map, a skill called terrain association. This task is far easier in mountainous or hilly areas than in areas where there is little to no reference, like in the plains or in a rain forest where your view is blocked.

The Huntsville quad isn’t the Rocky Mountains, so orienting a map is more challenging because you can’t simply look around and pick out the tallest peaks. That doesn’t mean that orienting the map isn’t possible. Notice how the map helps you visually see a valley? Close your eyes and imagine standing in the flat valley, somewhere near the ‘n’ in Robinson, then look east.

The map tells us that the valley isn’t heavily vegetated because it isn’t in green, but the hills to the east are. We also can tell from the contour lines that there is a significant elevation change of about 100’. It then becomes possible to visualize a slinking, rapidly rising set of hills with at least four distinct faces. (I’ve annotated the map with ‘you’ to show your position, and four red arrows to show the faces to visualize). Valleys are often easy to identify because there is typically a water feature running through the middle; the water feature is typically responsible for carving out the valley.

In this image we can see two hills sitting across from each other. The change in elevation isn’t as dramatic as one might find in Utah or Colorado, but it’s a saddle. The key to identifying a saddle is to look for concentric circles with a space between them. Someone once told me that a saddle can be thought of as a frying pan with two eggs on it. There’s the surface of the pan, then there’s an elevation gain up to the egg whites and then there’s the top of the two hills, the yolks. It’s a silly but effective way to understand that the saddle is the dip between the two areas of higher terrain.

Hills also stand out on a map and are shown as single concentric circles. Here is an example of a very small hill with only about 20’ above its surrounding terrain.

Reading terrains isn’t difficult, but it requires the ability to close your eyes and envision the surrounding area sometimes. Other terrain features can be picked out on a topographic map, including cliffs, spurs, depressions, ridge lines, and draws.

Next Week

Next week we’ll be digging into the venerable compass. Don’t run out and buy yourself a new compass just yet. After we cover the compass you’ll have a better understanding of the different types of compasses there are, and specifically what features you want to consider when purchasing one.

Note: The LandNav 101 series is using the Sam Houston National Forest as the training grounds for most of its cartographic adventures. If you’d like to download a PDF of the referenced topo map, it is the Huntsville 7.5 x 7.5 1997 map. It has an alternate ID of TTX1823, ISBN 978-0-607-93473-1. A printed version can be purchased from the USGS Store for $8.

In our last article on Land Navigation, Intro to Map Terminology, we introduced you to our LandNav series and went over the most common terms that get thrown around when dealing with maps.

Today we’ll be addressing what all those things in the margins of your map mean and how to best use them to your advantage when navigating.

The margins of a topographic map are rich with information. For the LandNav 101 series, we are going to be operating strictly against USGS maps. While other cartographic entities may vary their margin layout, most will contain all of the details covered herein.

Area and Scale

What’s the first thing most people do when picking up a map? They try to figure out what area the map covers! The top-right margin of USGS maps reveals the quadrangle, political boundary area, scale, and type of map. The map we’re working from is the Huntsville Quadrangle in Walker County, Texas and is a topographic map at a scale of 7.5 minutes, or 1:24 000—the most popular scale used by hikers, search and rescue teams, etc.

Knowing the scale of the map is important, but having a reference bar that facilitates “as the crow flies” distance estimation is even better. The scale can be found at the bottom center of the map. Here, the map re-enforces that a 7.5’ map is 1:24 000, and the three scale bars facilitate measuring distances in miles, feet, meters, and kilometers.

Measuring the distance on a two-dimensional printed map only estimates the distance; hence the reference to “as the crow flies.” This is because the topography of the environment isn’t considered; we live in a three-dimensional world. There is a difference in distance between a measurement on a map at the ocean’s edge versus a measurement across a mountainous landscape with perpetual ascents and descents. Remember, the focus of the series is on basic terrestrial navigation using a map and compass—so we aren’t going to talk about modern electronics that have the ability to compensate for these differences, that’s a future series.

The scale bar doesn’t place the 0 at the left end like one might expect. Instead, the first portion of the scale bar is delineated to facilitate fractional measurements. Looking closely at the MILES scale, starting at the 0 moving left toward 1 there are alternate shaded bars. Each bar represents 1/10 of a mile. Similar shaded bars exist on the feet and meters/kilometers bar, though the FEET bar provides a less granular measurement at 1/20.

Contour Intervals and Quadrangles

Immediately below the scale is another critical piece of information, the contour interval. Contrary to popular belief, Texas isn’t completely flat (and it isn’t all desert, either!). The distance between any two adjacent contour lines on this map represent a 10-foot elevation gain or loss. Looking at the shaded graphic, I’ve added text to count the lines from the 350’ contour line to the 400’ contour line. If you needed to travel from the top left corner of the un-shaded area to the center of the 400’ peak, you’d be gaining 50’ in elevation along the way.

There are two other important pieces of information near the scale bar before we move on to the other information in the margins. First, the elevation model is based on datum from a 1929 survey. This is critical (think of Mount Saint Helens) would elevation data be useful from 1929? Likely not, since the mountain blew its top the elevations in the area have changed dramatically. The second useful bit of data is a friendly reminder of how to convert feet to meters, multiply by 0.3048.

What exact area does the Huntsville Quadrangle cover? Immediately to the right of the scale is an outline of the political border for the great state of Texas. This obviously generalizes the location. Looking at the four corners of the topo map reveals the latitude and longitudinal coordinates for each corner, as well as UTM data (which will be covered in a future series article).

Let’s assume for a moment that you’re interested in hiking around the entirety of Lake Raven, located immediately above the Texas quadrangle location reference. How does one go about finding the next map to the immediate south of this location? Immediately below the quadrangle location is a very handy reference that shows the adjoining 7.5’ quadrangles. To ensure adequate coverage, we’d likely need to acquire the Moore Grove quad in addition to the Huntsville quad.

Legends and Declination

Moving still further right along the bottom margin of the Hunstville quad is a simple legend, or table of symbols found on the map. Unfortunately, this is rarely an all-inclusive legend. I printed and carry the USGS Topographic Map Symbols reference behind my map in my map case. Carrying an additional two sheets of paper in my load is negligible, and the ability to quickly reference rarely seen contour symbols, boundaries, coastal features, etc. is nice when you’re on an extended trip through the backcountry.

Located to the immediate left of the scale is the magnetic declination diagram, as calculated from the center of the sheet in the survey year. This diagram shows the angular relationship between Grid North, True North, and Magnetic North. We will cover Grid North in a future series article covering UTM. Likewise, a future series article will focus entirely on the venerable compass, including how to adjust the compass to take into account magnetic declinations.

Magnetic declination takes into consideration that the Earth’s poles are constantly shifting. I’m neither a geophysicist, nor did I spend the night at a Holiday Inn- so I’m not going down this rabbit hole any further! Suffice to say, knowing the current magnetic declination for the area you’re heading into is particularly important- your compass is going to point to magnetic north, not true north. If the map was printed years ago, the amount of magnetic shift could be very significant.

One of the most valuable utilities I’ve found for computing magnetic declination before heading into the backcountry is at the NOAA web site, Magnetic Declination Calculator. This calculator allows you to find the current or future (and presumably the past too) magnetic declination by entering in a specific lat/long, or a zip code if that’s all you have available to you.

It then asks for a date, so if you are planning your trip for next summer, you can predict the declination for that point in time. In the example, we see that the Huntsville quad declination for 26 September 2010 is 3° 20’ E, changing by 0° 7’ W per year.

Declination Apps

As an aside for those of you with an iPhone, it is possible to turn this calculator into an app icon on your main screen in 4 simple steps, saving you from having to remember the URL every time you want to look up a declination.

1. Launch Safari and search from NOAA Declination Calculator and select the correct www.ngdc.noaa.gov calculator search result to display the page
2. Click the + button to create a bookmark
3. Choose Add to Home Screen
4. Enter a name, e.g. Mag Decl

There are also a few apps in the AppStore that provide you with your current declination based on your current GPS location or searched location, but we haven’t tested these in depth yet. Just search “declination” in the Apple AppStore to get a look at these.

Notes

Everyone reads the margins of a map to figure out if the map contains the right information for the area of interest. Our next article will shift from the margins to the data found on the map itself. We’ll be discussing both map colors and terrain feature identification.

The LandNav 101 series is using the Sam Houston National Forest as the training grounds for most of its cartographic adventures. If you’d like to download a PDF of the referenced topo map, it is the Huntsville 7.5 x 7.5 1997 map. It has an alternate ID of TTX1823, ISBN 978-0-607-93473-1. A printed version can be purchased from the USGS Store for $8.

There’s an old saying wherever you go, there you are! Unfortunately that isn’t good enough, especially in a survival situation. Even a rough estimate of your position is far better than being totally clueless.

In the most ideal situation, you might have access to a GPS with fresh batteries—but even then successful wilderness navigation isn’t a guarantee. Remember back to elementary school math; they always taught the long, hard way before introducing the shortcuts that are used in the real world.

It is in this spirit that we are launching a new series on land navigation. We’ll start with the basics, progressing to more advanced land navigation topics.

Perishable Skill

Arguably the biggest challenge with land navigation is that it is a perishable skill. If you took a map course five years ago and haven’t picked up a map and compass since, odds are you remember about zero. An instructor I had once made a lasting impression on me with this line: You are as good as what you’ve mastered, not what you’ve been taught! Attending a karate class doesn’t make you a master- it takes years of practice, training, and dedication. Land navigation is no different.

Entire books have been written on how to navigate the Earth, and to re-emphasize an earlier point, our journey is going to span a series of interconnected articles specifically dealing with navigation on land. To cover everything in a single post simply isn’t feasible.

Navigation in general has its own vernacular, and using proper terminology is important. Some of the best references come from either the US Geological Service (USGS), or various military manuals. And with that, there’s no better place for us to start than formally defining what constitutes a map.

Map Definition

The most elementary definition of a map is nothing more than a picture representing a well-defined area. Maps have been around for as long as man, and the ancient art of drawing a map with a stick is still with us. There is a key lesson here: each of us conjured up a unique image in our mind when we read the word map, yet everyone of us have the skills to create an ad hoc map with nothing more than a stick and some dirt if we are out in the backcountry. Sometimes simple works!

In the backcountry there are few roads, and even less buildings and man-made landmarks. Getting from point A to point B is rarely a straight-line exercise. Natural formations like mountains, lakes, and rivers, and in some cases even the occasional bear might force you to choose a non-optimal route (not that I’m admitting that has ever happened to me in Montana…). Choosing a route is best accomplished with a topographic map, or simply a topo map.

Topo maps excel at presenting Earth’s distinguishing features and natural formations in a way that makes it relatively easy to define a path with a known exertion level. In other words, if you didn’t bring gear to scale El Capitan in Yosemite National Park, you best plan a route around the awe-inspiring granite. Topo maps use contour lines to represent a well-defined elevation. When contour lines are spaced very closely together, they represent a radical shift in elevation—like El Capitan. Notice how the contour lines converge, forming what is for all intents and purposes a solid line on the topo map. No one hikes up El Capitan!

Waypoints, Longitude and Latitude

The points plotted out along the planned path are known as waypoints. The value of the waypoint is in the eye of the beholder. It might represent a halfway point on the hike, the place to cross a river where it is at its narrowest/shallowest, or even the scenic vista where lunch will be served. Waypoints can be thought of as the backcountry equivalents to exits on a freeway.

The precise location of a waypoint is usually given using a coordinate system. Today, we are going to limit our discussion to latitude and longitude. Latitude is a horizontally running line that wraps around the Earth used to measure a distance north or south of the equator. Lines of latitude never intersect one another; they always run parallel to each other. In contrast, longitude is a vertically running line that always intersects the north and south poles. The longitude equivalent of the equator is the Greenwich meridian, or prime meridian, and lines run east and west of this meridian. More formally, both latitude and longitude measure angular distances using degrees, minutes, and seconds.

Map Scale

Quality maps are drawn to a given scale, or level of accuracy. Scale is a ratio; it equates a fixed distance on the map to an actual distance on the ground. One of the most popular scales for land navigation is 1:24,000, or 7.5 minutes in latitude and longitude. Maps of this scale from the USGS cover a quadrangle, or more simply a quad, which is a cartographic way of saying that the map is a four-sided area bounded by parallels of latitude that may or may not be of equal dimension.

One minute (1’) of latitude equals 1 nautical mile (1.15 statute mile or 1.85 km) regardless of map scale. One degree of latitude is comprised of 60 minutes, so it equates to 60 nautical miles (69 statue miles, or 111 km). Knowing that the most popular maps for land navigation are 7.5-minute maps, if one were to travel across the map, the trip would cover a distance of 7.5 nautical miles (8.63 statue miles or 13.89 km).

If you’re looking to find a topo map for a specific area of interest, be sure to check out the Map Locator at the USGS Store. Here you can find and mark places of arbitrary interest, then download or order a printed version right from the store. I routinely use the service when I have advance notice of a trip to the backcountry. After all, batteries go dead, and GPSs fall in the water, never to be seen again. Having a map, compass, and a reliable watch to fall back on is vitally important for extended backcountry excursions.

Notes

Knowing how to read a topographic map is a combination of art and skill. Today, we introduced key terminology that we will build off of in the articles ahead. The next article in this series is going to discuss the importance of the data found in the margins of a USGS topographic map.

For the truly motivated, we are going to be using Sam Houston National Forest as the training grounds for most of our cartographic adventures. If you’d like to download a PDF of the topo map we’ll be using to follow along in the coming articles, it is the Huntsville 7.5 x 7.5 1997 map. It has an alternate ID of TTX1823, ISBN 978-0-607-93473-1. A printed version can be purchased from the USGS Store for $8.

Photo by Pemb Dave

I have always liked fun trivia and details everyone else likes to skip over. One of those little items I like is marching cadence. It makes a hell of a difference when you run the numbers.

The US military uses a 30-inch step. Normal marching cadence is 120 steps per minute. That equals 3.4 miles per hour or a 17.64-minute mile.

Double Time is essentially a jog that uses a cadence of 180 steps per minute. That equals 5.1 miles per hour or a 11.76-minute mile.

Many readers will note that the Ranger/SF standard is 15 minutes per mile or 4 miles per hour. This is easily attained and maintained for long distances whereas double time is not.

A combination of Quick Time and Double Time can be used to attain overall speeds of 11-15 minutes per mile. This takes some practice. Start by adding 30-60 seconds of double time every 10-15 minutes of marching and gradually increase it over a period of many weeks.

Do not exceed 5-minute bursts of double time, especially with heavy loads. It is murder on the knees and hips. But it is a required skill for anyone in combat arms so practice it a bit so you know how to do it.

Never make running with a load a significant part of your PT program unless you want to retire early!

About The Author

Nathanael Morrison was a USAF Special Tactics and Pararescue team leader for 15 years before transferring to the US Army. He has written “the most complete book on military specific training ever published, Military Fitness: A Manual of Special Physical Training.”

He is available to teach or speak on a wide variety of military and special warfare subjects. Visit his web site at www.alpin-gruppe.com