Maps

An introduction

18 April 2000

By Will Adams


    ALLRIGHT!! LISTEN UP!!! Today's lesson is on MAPS: What is a map; what type maps are there; what do you need to look for on a map and finally; where can you find and buy maps?

A map is:

  1. Something you can never find when you need it.
  2. A Folded, warped, piece of paper, shoved under the passenger seat with bits of partially decomposed pogue bait covering it.
  3. Directions someone drew for you on a bar napkin while they were drunk.
  4. A graphic representation of the earth's surface (or a portion of the earth's surface) drawn to scale on a flat surface.
    Correct choice today is "D". Remember this: You will see this again (sounds familiar, doesn't it?). Maps are identified as - Planimetric, Topographic or Photomaps.  There are different types and scales but they all fall into one of these classifications.

    Now then, moving on rapidly, but without confusion... I hope.  We have Planimetric maps, better known as "civilian roadmaps".  Not much use to us "sniper type individuals", but they do give horizontal distance and other information like the next rest area but that's about it.

    Topographic (topo) maps are our friends (for the most part).  These maps show horizontal AND vertical positions and features, which shows the shape of the terrain (ground for you "civvies") by the addition of contour lines.  Rivers, woods, roads and hills are shown by lines, symbols and colors.

    Next are Photomaps.  These are either single photographs or an assembly of aerial photographs of an area to make a composite picture with gridlines, contour lines, marginal data and other information printed over the pictorial area.

    OK, we have covered... what a map is and types of maps.  A map is a graphic representation of the earth's surface drawn to scale on a flat surface.

    LISTEN UP AGAIN!!! You have 3 Scales in military topographic maps - Large, Medium, Small.  Guess which one serves you best?  Answer - ALL OF THEM!!  On a daily basis in your local AO (Area of Operation) or "da 'hood" to the "civvies", you would use a Large Scale map.  No, large scale does NOT mean a larger area but more detail of a smaller area.  The USGS and most (not all) mil-topo maps are large scale which is given as a Representative Factor (RF) such as 1:25,000 where 1 unit of measurement on the map equals 25,000 of the same units on the ground.

    Let's clear the air on some stuff.  ALL maps have scale, either stated or not.  For the record - military maps (referred from now on as topo, even if it is not military) and USGS (United States Geological Survey) use 3 scales as mentioned earlier.  The Standard Small Scale Map is 1:1,000,000 ... in other words, lots of area but very little detail.  A Medium Scale Map is one in which the scale is between 1:75,000 and 1:600,000.  Last is the Large Scale Map whose scale is 1:75,000 and larger.  These show lots of detail and provide us with very useful information, like, just how tall is Storm Mountain?  Anyone?  BTW, a large scale topo covers an area roughly 49 to 70 SQUARE MILES!!  A small scale map covers (again roughly) 73,000 to 100,000 square miles.  Now do you see what I mean about detail available?  A large scale map covers a smaller area in more detail and that's what is going to be discussed now.

    Before someone in the military or with prior service starts to blast me about some stuff... this is an overview, although slightly detailed about maps and map reading and where to purchase said items.  Any technical details, PLEASE, e-mail me!!  I am not going to discuss orthographic view, conic projection, or making a terrain study at this time.

    On a topo map there are FIVE (5) basic colors and they are:
BLACK - All man-made or cultural features on a map.  Railroads, roads, bridges. airfields. etc.
BLUE - All features shown in blue have something to do with water.  Things like shorelines, lakes, canals, swamps, etc.
BROWN - This is used to show elevation or relief by use of CONTOUR LINES.  A Contour Line is an imaginary line of equal elevation.  A series of contour lines will show the presence or absence of relief such as hills and valleys.
GREEN - This color indicates any feature that is some type of vegetation such as; woods, orchards, vineyards and grasslands.
RED - This color is used to show Main Roads, built-up areas and special features.

    Depending on your needs you will probably work with large scale 1:24,000 (USGS calls these 7 1/2 minute maps) or 1:62,500 (USGS 15-minute maps) where the 1:24,000 has a representation of 1 inch on the map equals 2,000 feet and the 1:62,500 has 1 inch on the map equals nearly 1 mile.  For you militaria or trivia "studs", a small scale map (remember, large area - little detail) is used for general planning or strategic studies, where the large scale maps (small area, lots of detail) are used for tactical, technical, and administrative needs of military field units.  Oh yeah,
medium scale maps are normally JOGs (Joint Operational Graphic).

    Let's see, we have covered what a map is "graphic representation of the earth's surface drawn to scale on a flat surface."  Types of scale: small, medium and large and we have learned that there are 5 basic colors - Black, Blue, Brown, Green and Red.  Also what those colors mean on the map.

Good enough!!  Take a break and the next part will cover how to read a map.

DISMISSED ! ! !


This portion of our discussion of maps will cover reading a map.  Let me make a comment/clarification on the last part.  I stated that USGS 15-minute maps are at a scale of 1:62,500 which is nearly 1 mile on ground per 1 inch on paper while the ACTUAL scale 1:63,360 1 inch on map DOES equal 1 mile on ground.  Just didn't want anyone to think I was "blowing smoke".

    At the top of the topo map will be a name.  This name is the "largest", best identified part of this map.  If you are using a military map it will have an alpha-numeric system of identification... more on that later.  At the bottom of the map you will find more information and it is normally called a Legend.  This Legend will have such information as scale distances, topographic symbols, road examples and etc.  You will also notice a group of lines, evenly spaced, going horizontal and vertical, creating a grid.  The squares of this grid help to locate "Points" quickly and accurately.  These squares are further numbered and from this you can find a location (point), give your location, and after studying the map long enough... figure out where you aren't if the person reading the map before you has "become disoriented".  Maps are read to the east from left to right and from the bottom up!! Because these lines measure distance eastward they are called "Eastings" and since you read the vertical lines from bottom to top and they measure distance northward, they are called "northings".

58 -|-----|-----|-----|-----|-
57 -|-----|-----|-----|-----|-
56 -|-----|-----|-----|-----|-
55 -|-----|-----|-----|-----|-
     30   31  32  33   34

    Using the above example, you will see that the 1st grid if read correctly would be 3055 and the northeastern most grid will be 3357.  Remember, READ RIGHT and UP! ! !  Always start in the lower left corner.  Always.  Every grid square comes from the two grid lines at the LOWER LEFT CORNER! ! !  Digest that for a minute or two and we will cover features next.

TAKE A BREAK


US Army Land Navigation and Map

    That is the "Source" for US Army Land Navigation and Map reading.  Of course I could be "tabbed" to discuss the finer points... just an idea.  One good thing about that site is that it is geared toward an 8th grade reading level! ! !  No Lie! ! !  Go to the site and check it out... very simple reading.  Also that site has "pretty pictures"!! hee hee hee


    This portion of the discussion has to do with where to acquire maps/waterproofing maps and other gear you might need, like compasses etc.

    Earlier there was a description of what a map is and the different scales.  I'm going to repeat myself but bear with me... this might make things easier to understand.  A small scale map covers lots of ground but not a lot of detail.  Several medium scale maps will make up one small scale map.  Last but not least... a whole bunch of large scale maps cover a medium scale map.  Almost like a puzzle where little pieces combine to make a larger piece and those connect to make the puzzle whole! !  I realize that is very simplistic but I'm limited in being able to draw...

    Now that that's said and done... where do you locate, buy maps.

    Online, I go to USGS National Mapping Information, to me that is "the Source" for maps of the U.S.  Remember, I am primarily concerned with topo maps but you can also go to Delorme Maps and Mapping Software  or MapBlast!.  You can also find  maps in some malls where there is a map shop and really good outdoor specialty shops carry maps (especially for climbers and hikers).

    As to learning more about maps an how to use them... one of the easiest to understand is the US Army's Field Manual, FM 21-26 Map Reading and Land Navigation.  If you prefer a civilian book that is excellent then chase down a copy of, "Be Expert with Map & Compass" by B. Kjellstrom, probably available at Amazon.com.  If you want to improve your skills with map and compass then take up the sport of Orienteering.  The site for that is the US Orienteering Federation.  IMHO, orienteering is a great way to hone your skills in cross-country movement. Check it out.


How to Waterproof Maps

    One way is to use clear contact paper but that makes the map very difficult to write on and can be a real pain to do properly.  There is a product called "Stormproof" available at most map shops and outdoor specialty stores that really works as the name states.  FOLLOW THE INSTRUCTIONS ! ! !  This stuff coats the paper, makes it waterproof, flexible, and you can still mark on it.  Then there is the tried and proven method of stuffing the map in a zip-lock baggie!! Its grease pencil friendly and marker friendly.  Not perfect but it does work.

    OK, now the fun stuff... I am NOT EVEN going to talk about GPS...unh unh.... no way!! I'll deal with the mundane run-of-the-mill compasses!!  The military lensatic compass works and is simple in design.  Being the prudent person I am I always carry a back-up, especially when it comes to something so important, and for that matter have been known to have another stashed in my gear somewhere.  However, the back-ups were not military but either a "SILVA" brand or a "Brunton" model.  Just remember that you get what you pay for!! It is your butt lost in the woods and its getting very miserable and all because you bought the "el cheapo" hang from the zipper, or the type you can attach to your watch, forgetting that your watch is not de-magnetized!!  You can buy a good quality compass for as low as $20 and get an almost "Top-of-the-Line" for under $70.  Good sources for compasses are Cabela's, Brigade Quartermaster and U.S. Cavalry Store.


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