Map Basics
Return to Topics

Modules:
1. Different Kinds of Maps
2. N. S. E. W. Adjoining Maps
3. Map Symbols
4. Contour Lines
5. Introduction to the Compass
6. Measuring Distance on a Map
Answers to Practice Questions

E-mail Bryan at
Outdoor Adventure

Welcome
If you are reading this chances are you're interested in adventure and exploration, seeing new things and going to new places. Maybe you are an avid hiker, skier or mountaineer. Whatever outdoor pursuit you enjoy, you are interested in adding to your "quiver of skills" or maybe you feel that it's time to review those old map skills that have gotten a bit rusty.

Completing a course like this will contribute to your enjoyment of the outdoors. It shows the commitment you have to developing your outdoor skills and the value you place on enjoying wild places safely. Plus, you can relax a bit and take comfort in the fact that you know where you are and where you are going!

What will I get from this course?
The goal of this course is to teach you some basic map skills that will help you plot a route on a map, follow that route and avoid an unplanned and dreaded night out under the stars.

By the time you are done with this course you will:
· Be able select the proper map for your intended use
· Orient a map to North
· Identify many of the symbols on a map
· Identify the shapes of geographical features
· Measure distances on a seven and a half minute map

This course should be fun. We're sticking to the basics throughout so it won't get to technical. Take another course for the more advanced stuff. Or, get with a friend, buy a good orienteering book like the Land Navigation Handbook by W.S Kals and work out the tricky stuff together. This course will help you get started and sometimes that's the hardest part.

Relax, enjoy…and good luck on all your adventures!

How's this going to work?
So now your ready to start and you need to know how this is going to work. Well, the course is divided into six modules. Each module has an objective listed at the beginning. It's best to go in order but feel free go back for review or jump forward if you are curious.

Before you get started with the modules, take a few moments to look over the sample maps. See what looks familiar, what you already know and what you would like to learn about maps. If you have a topographical map of your own, take a look at the margins, there is a lot of information about the map there. Can you tell what some of the symbols mean? Take a moment to get familiar with your map and the map samples you'll find in this course and other maps will begin look familiar too!

Ready to get started?
Before you begin, here are a few pointers that will help you get the most from this course:
o First, consider the objective, take a moment to reflect on how that objective might be useful to you on your next adventure.
o Read the lesson
§ Refer to a sample maps frequently, after all that is what this course is all about
§ Notice at the bottom of some of the pages there are key term and definitions
o Think about the examples you'll find in the modules, they are there to help you understand new concepts.
After you are done with all the modules, take some time to review o Check out the map samples or get your own map out one more time and look it over the some way you did before you began the course, do you recognize more features now?
o Review the objectives, rework any that you aren't sure of.
If you are comfortable with the material, go ahead and complete the assessment questions section.

Top

United States
Geological Survey

Module 1: Different Kinds of Maps
Objective: Choose the appropriate map based on your needs
There are many different maps available from hand drawn directions to a friends house to elaborate decorative maps to maps that show underground geological features. Most people are familiar with road maps, we use them often. Another common type of map is the topographical map, also called a "topo". Hikers and other outdoor folks use these maps a lot. Topo maps have lines on them that represent different land features and shapes such as mountains and valleys. We will explore these lines in Module 4.

The most common topos are seven and a half minute maps. Seven and a half minute maps cover a small area and show a lot of detail. We want to see as much detail as possible when we are planning a hike. These maps are produced by the United States Geological Survey (USGS) and are available directly from them or at many hiking shops.

There are topo maps that cover larger areas and still show a lot of detail (such as the Trails Illustrated® map, pictured at the left) These are published for popular recreation areas and can be useful. The skills we will practice on seven and a half minute maps can be transferred to these larger land area maps.

Different maps are intended for different uses: Highway or road maps may show a large land area and elevations, rivers, streams and lakes but they aren't especially accurate and don't have a great deal of detail. After all, what do we care, as we zip along at 60 MPH about a bridge over a stream or a hill on the highway. But, if we were walking in the wilderness, a stream or hill might have a real effect on our day and a river we didn't plan on might just ruin a whole hiking trip!

So, we would choose either seven and a half minute, USGS maps or, perhaps, commercially published maps like Trails Illustrated® that show the information and detail we require as backcountry users. The kind of maps that show the features we will learn more about in this course.

Map Fact:
Did you know that maps used for navigation on the sea are called charts and that there are topographical charts that map the bottom of the ocean?

Module 2: North, South, East and West, Adjoining Maps
Objective: Orient the map to North and identify the names of the maps that adjoin your map.

The top of every seven and a half minute map represents the Northern most region of the area covered by the map. If you lay your map down and turn it so that you can read the information at the bottom and look toward the top, you are looking toward North on the map.

If you face "North" on your map, notice that west is on your left, east is on your right and south is at the bottom of the map.

Look at the margins, you will notice that there are name of the adjoining quadrangles The sides (East and West), top (North), bottom (South) and corners (North East, North West South East and South West) have the names of the adjoining maps printed there.

If you have your own map, take it out and look at the map key and some of the other information that appears in the margin. Do you know what these things mean?

Practice:
If you had the MT. DERK Quadrangle and your planned hiking trail left the map at the very top, what map would you need to get to see the rest of the trail?

Module 3: Map Symbols
Objective: Identify important surface features that will help you plan routes and tell where you are on the map.

There is a lot of stuff out there, bridges, building, swamps, trails, roads, the list goes on and on. Cartographers have come up with symbols to represent just about every surface feature you can think of, man made or natural. You will need to be familiar with the most common of these to be proficient with a seven and a half minute map.

Listed below are most of the symbols you should know. Depending on where you go, you may see other symbols, but this list should cover most of what you will see on a seven and a half minute map of a mountainous region. If you're planning a hike along the coast you'll have to learn some new symbols.

Module 4: Contour Lines
Objective: Envision the shapes of a geographical features based on the contour lines of a seven and a half minute map

You might have figured out by now that all those light brown lines on topo maps refer to the shape or contour of the ground. But how does it work? How do two dimensional maps represent three dimensional land forms?

On a seven and a half minute map, each of the contour lines represent a certain altitude, that is to say, each line represents the same altitude for it's entire length.

To envision this, suppose you stood at a spot on the side of a hill one hundred feet above sea level. If you started walking around the hill at the same level (maintaining an elevation of 100) until you returned to the place you started from you would have completed one contour of the hill. Suppose you still had a lot of energy so you walked up the hill 40 feet and walked all the way around again, viola, another contour! If you were inclined to, you could continue this process until you reached the top of the hill.

If you did, you would know that hill pretty well by the time you were done. Fortunately, you can learn almost as much about the topography of a hill by looking at the contour lines of a topo map

The difference in elevation between lines is the contour interval. On seven and a half minute maps the interval is 40 feet. Every fifth line is an index line, it's a bolder line and has the elevation printed somewhere along its length.

Look at the contour maps (upper) and the three corresponding pictures (lower) to the right. Notice that as the hill gets steeper (left to right) the contour lines get closer together. If you look at the map on the next page you will notice that the lines get very close together on the North side of Hallets Peak, this is very steep, nearly vertical (get the rope out) terrain!

Practice: If the contour interval is 40 feet, what is the distance between index contours?

Look at the map below and compare the contour lines with the profile they are matched up to. Can you see how the shape goes with the contour lines?

Module 5: Introduction to the Compass
Objective: You will be able to identify the parts of the compass and how to use a compass to orient a map to magnetic North.

There is a lot to learn about the compass and its uses. What we hope to accomplish here is to give you an overview and an introduction to the basic use of a compass. Take an orienteering course to learn more about using a compass. If your compass looks different, don't worry, the parts are all basically the same

It is not necessary to orient a map to North to use it but it might be helpful. Particularly if you are trying to identify features you can see or if you are trying to approximate your location on a map using features you can see.

To orient the map toward North, all you need to do is lay the map out, place your compass on the map aligned with the left or right margin then rotate the map and compass together until the red arrow of your compass points to North. Now your map is aligned with magnetic North.

Module 6: Measuring Distance on a Map
Objective: After completing this objective you will be able to measure the distance between two points and calculate the distance you will have to walk if you are planning a hike.

Somewhere on just about every map you will find a scale of miles. On a seven and a half minute map you will find a scale at the bottom, center, it's right down there with the contour interval and some other stuff. Every seven and a half minute map has a scale of 1:24000. That means that an inch on the map is equal to 24,000 inches on the ground. In other words, every two and a half inches equals about one mile (2.64" = 1 mile).

If you are measuring a distance on a map, a ruler is very helpful for straight line distances. If you are interested in finding out how far you will be walking you might need to measure a curling and circuitous route. A string or thread (preferably not to stretchy) is just the thing for this. You can use the string to trace along your planned route, then holding the end where you began measuring and the spot on the string that ended up at your planned destination you can compare it to the linear scale at the bottom of your map and, there by, calculate the distance.

Try it out
look at the map below, notice the straight line and the curvy line. One follows a trail and the other takes a straight route. If you have your own map, take it out, get a ruler and a length of string. Now, find a trail on your map and compare the route a trail take to a straight line route
· How do the distances compare?
· How does the curvy route look to you, would it be good hike?
· How about the straight line, would that be good hiking route? Why? Why not?

Practice: Why do all USGS seven and a half minute maps have the same scale?

Answers to Practice Questions
The greater the area covered by a map, the lesser the detail.

If you had the MT. DERK Quadrangle and your planned hiking trail left the map at the very top, what map would you need to get to see the rest of the trail? The Manitou Quadrangle

If the contour interval is 40 feet, what is the distance between index contours? 200 Feet

The lines of contour are closer together or further apart on steeper hills? Contour lines are closer together on steeper hills

If you face North, what direction is to your left? West

Why do all USGS seven and a half minute maps have the same scale? Because the maps are all the same size and cover the same earth surface area, 7.5 minutes latitude X 7.5 minutes longitude

Top