A topographic map encodes three-dimensional terrain on a flat sheet using contour lines. Once you can read the four or five common patterns, you can look at a map and picture the ground — which is what makes it a navigation tool rather than a decorative object.
- 1
Contour lines and the interval
Every point on a contour line is the same elevation. The contour interval, printed in the map legend, is the vertical distance between adjacent lines — commonly 40 feet or 20 metres. Lines close together mean steep ground; lines far apart mean gentle. Cliffs appear as lines so close they merge.
- 2
Read scale and measure distance
A 1:24,000 map means one inch equals 24,000 inches on the ground, about 2,000 feet. Use the printed scale bar rather than doing arithmetic. Remember that map distance is horizontal — a steep mile is longer to walk than a flat mile and takes considerably more time.
- 3
Recognise ridges and valleys by the V
This is the pattern that unlocks the rest. Contours crossing a drainage form a V pointing uphill, toward higher ground. Contours crossing a ridge form a V or U pointing downhill. If you can tell a ridge from a gully at a glance, you can follow terrain rather than just following a line.
- 4
Spot saddles, summits, and depressions
A summit is a small closed contour with higher ground inside. A saddle is the low point between two summits, appearing as an hourglass of contours — and saddles are usually the easiest crossings between drainages. Depressions are closed contours with small tick marks pointing inward.
- 5
Estimate time, not just distance
A common approach adds roughly half an hour per 1,000 feet of climb to your flat-ground pace. Count the contour lines your route crosses, multiply by the interval, and you have your elevation gain. This is what turns a map into a schedule.
Trip planningTurning map reading into a day planRead Guide → - 6
Check the declination note
Maps are drawn to true north; compasses point to magnetic north. The difference, called declination, is printed on the map and varies by location and over time. Ignoring it introduces a bearing error that compounds over distance.
Using a compassApplying declination correctlyRead Guide →
Contour Patterns
| Pattern | What it means |
|---|---|
| Lines close together | Steep ground |
| Lines far apart | Gentle ground |
| V pointing uphill | Drainage, gully, or stream |
| V or U pointing downhill | Ridge or spur |
| Small closed circle | Summit or high point |
| Hourglass between summits | Saddle — often the easiest crossing |
| Closed contour with tick marks | Depression |