Scout Zone

Map Reading 🗺️

Read contour lines, identify terrain features, measure distances, and orient your map for Australian bush navigation. Covers Bushwalking OAS Stage 2 and above.

Introduction

What is a Topographic Map?

A topographic map (or "topo map") shows the shape of the land in two dimensions. As well as marking tracks, rivers, vegetation, and man-made structures, it uses contour lines to show how high or low every part of the ground is. This lets you plan a walking route, estimate how steep a climb will be, and figure out where water will flow.

Australian bushwalkers and Scouts most commonly use 1:25 000 maps produced by Geoscience Australia. These cover a relatively small area in high detail, showing every creek and ridgeline.

Key Skill

Contour Lines

Every contour line connects all the points on the ground that are exactly the same height above sea level. They are the most important information on a topo map.

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Contour Interval

The height gap between each line

1 The contour interval is the difference in elevation between two neighbouring contour lines. On Australian 1:25 000 maps it is usually 10 m. On 1:50 000 maps it is usually 20 m.

2 Close together means the slope is steep. Far apart means the slope is gentle. Evenly spaced lines mean the slope is uniform all the way up.

3 Every 5th contour line is an index contour. It is drawn thicker and usually has the elevation printed on it so you can read the height without counting every line from sea level.

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Reading Tips

How to interpret contours quickly

1 Contour lines never cross each other (except at an overhang or cave, which is rare on bush maps).

2 The numbers printed on index contours always read uphill. If you can see the number printed the right way up, you are facing uphill.

3 Count the lines between two index contours to work out the interval. If there are 4 ordinary lines between two index contours labelled 100 m and 200 m, each line represents 20 m.

Terrain Reading

Terrain Features from Contours

Different shapes in the contour lines tell you what the ground looks like. Learn to spot these six features and you can read any topo map.

Hill / Summit

Contours form concentric closed circles. The innermost circle is the highest point. May be marked with a spot height or trig point on the map.

Valley

Contours form a V or U shape pointing uphill toward higher elevation. Water flows along valleys. If you see a blue river line, it will follow the V.

Ridge

Contours form a V or U shape pointing downhill toward lower elevation. A ridge is a raised elongated feature. The V tip always points away from the high ground.

Saddle / Col

An hourglass shape in the contours between two high points. A saddle is a low point connecting two hills. It is the easiest crossing between two ridges.

Spur

A smaller ridge extending from a main ridge or hill. Contours bend away from the high ground. Spurs are common in Australian bush terrain and are easy to follow as walking routes.

Cliff

Contour lines are very close together or touching. This indicates a cliff or extremely steep drop. Never approach a cliff edge in the bush without checking the map first.

Planning Your Route

Map Scale and Distance

The scale of a map tells you how much the real world has been shrunk to fit on paper. Knowing the scale lets you measure real distances from the map.

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Common Map Scales

Used on Australian bush maps

1 1:25 000 — The most common scale for bushwalking. 1 cm on the map equals 250 m on the ground. High detail: tracks, creek crossings, and individual buildings are shown.

2 1:50 000 — Covers a larger area but with less detail. 1 cm on the map equals 500 m on the ground. Good for planning multi-day trips.

3 The scale bar at the bottom of every map lets you double-check by placing a ruler or piece of paper against it.

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How to Measure Distance

Using a piece of string

1 Lay a piece of string along your planned route on the map, following every bend and corner.

2 Straighten the string and measure its length in centimetres with a ruler.

3 Multiply by the scale factor: on a 1:25 000 map multiply by 250 to get metres. Divide by 1000 to get kilometres.

Worked Example

Your planned route on a 1:25 000 map measures 8 cm along the string.

Multiply: 8 cm × 250 m = 2,000 m = 2 km on the ground.

On a 1:50 000 map the same 8 cm would equal 8 × 500 m = 4,000 m = 4 km.

Distance Calculator

Map distance (cm)

Map scale

Field Skill

Orienting Your Map 🧭

Before you can use a map in the bush, you need to orient it so features on the map match what you see in front of you.

Place your compass flat on the map. Hold the map horizontal and lay your compass on top of it. Make sure the map is not tilted.

Rotate map and compass together. Turn the whole map (with the compass sitting on top) until the compass needle points to the top of the map. The top of a topo map is grid north.

Your map is now oriented. Features on the map (hills, tracks, rivers) now match the direction you would see them in real life.

Find two landmarks. Look around and pick two things you can see clearly: a hilltop, a road bend, a tower, a river. Find each one on the map. If both match up, you know exactly where you are standing.

You are now located. You know where you are and which direction everything else is. Keep the map oriented as you walk so it stays matched to the real world around you.

Note: Magnetic North vs Grid North

There is a small difference between grid north (the top of the map) and magnetic north (where the compass needle actually points). In most of Australia this difference is small. For Scout navigation at Stage 2 level, the difference is small enough to ignore. Your leader will explain magnetic declination if it becomes relevant on a longer expedition.

Test Yourself

Map Reading Quiz 🗺️

10 questions on contour lines, terrain features, and map scale. See how well you know your topo map!