How Not to Get Lost: Basics of Map Reading and Location Finding

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Introduction: How Not to Get Lost: Basics of Map Reading and Location Finding

About: I want to be a maker, and I am currently practicing and honing my skills. As I get better I will do more and more instructables!

Introduction:

To avoid getting lost during an extensive hike, a un-plotted hike, a multi-day hike, or a backcountry hike use—a map, a compass, other ways to find directions, and most importantly common sense.

You will learn what you need to know about maps and direction finding so that you can move about with confidence without getting lost. A map is nothing more than a drawing of a section of the earth’s surface as you would see it if looking straight down from an airplane.

Maps show man-made objects, such as roads, buildings, and bridges. All these man-made objects are represented by a symbol. The symbols are explained in the legend, located at the lower left-hand corner of every map.

Besides giving symbols for man-made objects, the legend gives the color coding used on the map and explains the meaning of other symbols, which gives you a better idea of what the ground looks like. Always look at the legend before using your map.

Disclaimer:

This tutorial already assumes you know how to use a compass and are familiar with compass-like terms.

Step 1: Finding Your Location

To avoid getting lost, you must know how to find your location. There are no street addresses in the wilderness. However, by using a map, you can find your location without difficulty. Maps have black lines running up and down (north and south) and crosswise (east and west). These lines form small squares called “grid squares” that are numbered along the outside edge of the map picture. Using these numbers, you can identify each grid square.

No two squares have the same number. To get the right numbers for a certain grid square, read from left to right along the bottom and locate the line that borders the grid square on the left. Then read up and find the east-west line that borders the grid square along the bottom.

The coordinate scale and protractor is a square piece of clear, thin plastic—called a “protractor” for short. The protractor helps to measure small distances inside grid squares. You can also measure angels with it.

So looking at our pictures we would read the grid as 4085. So we will be using the grid square 4085 for most of this tutorial. So the first 4 numbers in a point give you the grid square the next two numbers you can add will give you a 100-meter by 100-meter area. In our example, we found that we are closest to the number 2 on our bottom and closes to the number 4 on our top. So this 6-digit grid would be written as 402854. If we wanted to increase our accuracy to a 10 meter by 10-meter area we could add the decimals we approximated which were 2.1 for the bottom (21) and 4.4 for the top (44). This 8-digit grid would be written as 40218544. If you had an extremely accurate protractor (or were really good at approximation) you could add the second decimal to each number for a 10-digit grid which would give you an accuracy of 1 meter by 1 meter. I will use zero's to depict how to write this 4021085440.

Note:Since the outer edges of the protractor are the degrees or angle, it is recommended to put a bit of 550 cord through the center hole. This allows for you to center your point and shoot your azimuth on the map with the string to check out your route.

Step 2: Determining the Distance

You can use your map to measure the distance between two places because maps are drawn to scale. This means that a certain distance on the map equals a certain distance on the earth. This scale is printed at the bottom and top of a map (for example, Scale 1:50,000). This signifies that 1 inch on the map equals 50,000 inches on the ground. Any ground distance equals 50,000 times that distance on the map.

Note:The map I am using is a 1:165,000, my protractor (as we will see in the next step) does not have an accurate depiction of this map, but it will still work for what we are doing.

Always check the scale on your map before trying to measure distance, because different maps have different scales.

Two methods used to determine distance are the—graphic (bar) scale method and the pacing method.

Graphic (Bar) Scale Method:

There are three different bar scales at the bottom of your map. Use these scales to help convert the map distance into miles, meters, or yeards. To figure the distance on the ground use the graphic (bar) scale method, take the edge of a piece of paper and put a tick mark on it at the straight-line distance between your two points. Then put the paper beneath one of the bar scales and read the ground distance in miles, meters or yards.

Suppose you want to find the distance between point A and point B around a curve in a road. Take a strip of paper, make a small tick mark on it, and line up the tick mark with point A. Align the paper with the road’s edge until you come to a curve, make another tick mark on the paper and on the map, then pivot the paper so it continues along the road's edge. Repeat this until you get to point B, always following along the road’s edge with your paper. Make a mark on your paper at point B, then go to the bar scales to find the distance.

Pacing Method:

Note:A pace count is an important tool, you should practice using a pace count and you should always remember what your pace count average for flat and hilly terrain is.

When you have to go a certain distance on foot without any landmarks to guide you, you can measure distance pretty accurately by counting your paces. The average pace is just a little less than 1 meter. The average person uses 116 paces to travel 100 meters.

Note:You can find what your pace is by marking out 100 meters and counting the number of steps it takes for you to reach it. This is known as your pace count.

When traveling cross-country, you will use more paces to travel 100 meters—usually about 148 instead of 116. This is because you are not traveling over level ground and must use more paces to make up for your movement up and down hills. Pace yourself over at least 600 meters of cross-country terrain in order to learn how many paces it takes you to travel an average 100 meters. Be sure you know how many paces it takes you to walk 100 meters on both level and cross-country terrain.

The big problem with pacing is maintaining a straight line. At night, the average person tends to walk in a circle when not using a compass. During the day, you should use a compass and steering points (well-defined objects in your direction of travel). Also, remember to figure only the straight line distance when you have to walk around an obstacle.

Another problem with pacing is keeping count of the paces that you have taken. One way to keep count is to use pebbles. For instance, suppose you want to pace off 1 kilometer (1 kilometer is 1,000 meters or the distance between two of the black grid lines on your map). Put 10 pebbles in your right pocket. When you go 100 meters, move one pebble to your left pocket and start your count over.

Note:You can get the same effect by using a string with beads or tying knots in a string. In this case every 100 meters you would move a bead up or down depending on your preference.

When all 10 pebbles have been moved to your left pocket, you have traveled 1 kilometer.

Step 3: Azimuth

The top of the map is north, the right is east, the bottom

is south, and the left is west. The direction from one point to another point (either on the map or on the ground) is called azimuth.

Azimuths are given in degrees in a clockwise direction. Since there are 360 degrees in a circle, your azimuth can be any number up to 360. Due east is 90 degrees, due south is 180 degrees, due west is 270 degrees, and due north is 360 degrees.

To get the right azimuth from a map, you have to use a protractor. If your coordinate is 220850 and you want to find the azimuth to a certain road junction, draw a line from your location to the road junction.

Be sure to line the protractor up properly, keeping the cross-center lines of the protractor parallel with the grid lines. The azimuth as shown by the protractor is 223 degrees. Suppose you follow the 223 degree azimuth to the road junction, and then you want to go back to your original location. To do this, you must take a back azimuth. Simply subtract 180 degrees from the first azimuth (223-180 = 43 degrees)

If your first azimuth is too small to subtract 180 degrees, just add 180. For example, if your azimuth was 40 degrees, you know that you cannot subtract 180 degrees from it, so add 180 (40+180 = 220 degrees). Remember, a back azimuth goes in the opposite direction from the azimuth.

Note:When converting azimuths to back azimuths, use extreme care when adding or subtracting the 180 degrees. A simple mathematical mistake could have disastrous consequences.

Step 4: The Types of North

The north-south lines on a map give grid north. The compass needle points to magnetic

north. Grid north and magnetic north usually have a few degrees difference. Neither points straight at the North-Pole—That’s called “true north.” However, it is not necessary to know where true north is to avoid getting lost.

The difference in degrees for every map between grid north and magnetic north is shown at the bottom of the map. This difference is called the “G-M angle”. The diagram at the bottom of newer maps shows how to change grid azimuths to magnetic azimuths and magnetic azimuths to grid azimuths.

For example, you aim your compass at a distant tower and get a compass reading of 190 degrees. This is called a magnetic azimuth. The diagram on the map shows that the G-M angle is 2 degrees to the compass reading of 190 degrees. This gives you a grid azimuth of 192 degrees. Most of the time, the G-M angle is so small that you do not have to be concerned with it. It depends on what region of the world you are in.

Step 5: Resection

Use resection to locate your position when you do not know

exactly where you are.

Step 1: Orient your map as closely as possible.

Step 2: Look for a feature, such as the water tower, that you can find on the map.

Step 3: put a ruler (or anything with a straightedge) on the map, and place its edge right next to the water tower symbol on the map.

Step 4: Align the ruler so that it points exactly at the real water tower.

Step 5: Draw a line along the ruler (the line will cross the water tower symbol on the map).

Step 6: Find another feature, such as the road junction, and do the same thing.

When you lay the ruler on the map and point at the real road junction, its edge crosses over the road junction on the map. Draw another line along the ruler until it crosses (intersects) the first line. The point where the lines intersect is your location. This procedure is called resection. A third line may help you locate your position more accurately. Remember to not move your map once you have it properly oriented.

Step 6: Modified Resection

The modified version of resection is super easy so I didn't bother uploading a picture depicting how it's done. If you can do resection you can do the modified resection.

If you know that you are located somewhere along a certain linear feature on the map, such as a road or river bank, then you can use a method called modified resection to pinpoint your location. This is an easier method to use.

Step 1: Orient your map.

Step 2: Locate a feature that you can also find on the map, such as the water tower in the previous example.

Step 3: Put a straightedge through the water tower symbol on the map and align the straightedge so that it points exactly at the real water tower.

Step 4: Draw a line along the ruler. The point where the line crosses the linear feature you are on is your location. If you do not have a regular straightedge, you can use something such as your compass edge, a knife edge, a shoelace, a piece of cordage or even small stick.

Note: Always orient your map as closely as you can--using your compass is the best way.

Step 7: Intersection

Suppose you want to find the location of a certain object that you can see in the distance, such as a rock face, but it is not on your map. Use the intersection method as follows:

Step 1: Shoot an azimuth to the object using your compass. If you have to, convert the magnetic azimuth to a grid azimuth.

Step 2: Draw a line on the map from your location along the grid azimuth that you came up with. The Rock face lies somewhere along this line.

Step 3: Move to another location where you can observe the same rock face and shoot an azimuth to it.

Step 4: Convert the azimuth from magnetic to grid, and draw it on your map (out from the point where the azimuth was taken).

The rock face lies where the second line intersects with the first line.

Step 8: Determining Relief and Elevation

Most maps that you will use for hiking are called topographic maps, these maps show contour lines that represent relief and elevation (the slopes, hills, and valleys). We have already talked about locating points, measuring distances, and finding the right direction. Skills every hiker should hone. But, you should also check hills and valleys along the direction you intend to travel before you start.

Relief is the representation (as depicted by the mapmaker) of the shampes of hills, valleys, streams, or terrain features on the earth's surface. Elevation is the vertical distance of a point on the earth's surface above or below sea level. There are several methods used by mapmakers to depict relief and elevation of the terrain.

Contour lines are the most common method used on mpas. A contour line is shown as a brown line that connects points of the same elevation. Each line depicts the height above sea level. Contour lines never cross one another.

Printed at the bottom of the map is the contour interval--the difference in height (elevation) between one brown line and the one next to it. On a map with a scale of 1:50,000, the contour interval is usually 20 feet.

The rate of rise or fall of a terrain feature is known as its slope. Widely spaced contour lines show a gentle slope; closer contour lines show a steeper slope. You can tell from looking at your map what the slopes, hills, and valleys will look like on the ground.

Contour lines across a stream always come together in a V-shape.

When the contour lines are close together at the top of a hill, the hilltop is pointed. When the contour lines are widely spaced at the top, the hilltop is flat.

The legend on the map shows water as blue. To determine the direction the water is flowing, look at the contour lines. The V-shape always points upstream or toward high ground. Looking for a stream is a good way to find valleys.

Sometimes contour lines show two hilltops fairly close together. The lower the terrain between the two hilltops is called a saddle.

If you are in a saddle, there is high ground in two opposite direction and lower ground in the other two directions. A saddle is normally represented as an hourglass shape. Going through a saddle is sometimes the easiest route to use to get beyond the two hills.

Another terrain feature you should be familiar with is a ridge. A ridge is a fairly long, narrow section of terrain. If you are standing on a ridge, the ground will go uphill in one direction and downhill in the other three. Contour lines that form a ridge tend to be either U- or V-shaped. The closed end of the contour line points away from high ground. The path of the ridge, depending on your geographic location, may be either an almost unnoticeable slope of a very obvious incline.

You can also use contour lines to determine the line of sight from one point to another. For example, you are at point A and you want to see point B. To determine the line of sight, draw a line from A to point B on your map. Note that it crosses some contour lines with higher elevation than both points. Therefore, you know you will not be able to see point B.

Step 9: Conclusion

We have talked about how to find your location and write it as a six-digit number coordinate. You have also learned how to measure distance, find directions, and read contour lines. If you use this information, you can avoid getting lost. Practice and review this information before you have to navigate. Do not wait until you are lost before trying to remember what you should already know about map reading and land navigation.

It's also very important to do some research on the area's you wish to go to about the weather conditions and animal life. Sometimes there are higher threats of poachers and nefarious activity depending on where you are located. Hiking is fulfilling, fun, and exhausting, don't give up and don't get lost!

Let Me Know What You Thought:

Now message me or comment below if you need me to make a video for this (I primarily didn't because I don't have the best set up to make one, but if I have enough support I can get a good set up). I can also point you in the direction for some good resources if needed and if there is a portion you don't think I explained clear enough or needed better examples I would be more than happy to make those! Like I said in the beginning though this tutorial already assumes that you know how to use a compass and shoot an azimuth, this is supposed to just be a tutorial for reading a map and finding your location on a map. If other tutorials need to be created for how to use a compass and alternate methods of finding direction when a compass isn't available please comment below and I'll try to make it happen!

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    4 Comments

    Your grid squares are wrong. Always keep East/west numbers together along with North/South. If you are on grid 4085, your next coordinate would be 402854, not 408524.

    The lines that run vertically are E/W lines, the horizontal are N/S lines. So reading up will give you the N/S line, not the E/W line. This is important, E/W is the first reading, N/S is second. So in actuality you are on grid 8540.

    What you call resection is also called triangulation.

    Each square is called a click, the reason that in the military "click" is slang for a kilometer.

    Easiest way to find your location though is to have an assistant shake a tree, then look for the shaking tree on your map. (joke we used on the newbies in the Army).

    1 reply

    Thanks, I totally screwed that up, I'll update it. I've also never heard of resection being referred to as triangulation, that's a good tip in case others aren't familiar with the term resection. You know it has been a bit since I've done a land nav course, but I'll say I've never heard that joke! The last land nav course I had to take was about 5 years ago when assessing for 'Green Platoon.'

    Map reading can get pretty confusing; thanks for sharing all this great information :)

    1 reply

    No problem! I'm glad you found it useful, I've just picked up a thing or two while being in the military and thought it would be nice to share some of my knowledge!