Map skills

How to read contour lines

Contour lines connect points of equal elevation. They turn a flat map into a picture of the ground: the steeper the slope, the closer the lines.

Quick rule

Every contour line is the same height above sea level. Moving from one line to the next means gaining or losing one contour interval; use the labelled index lines to determine that interval.

1. Start with spacing

Lines close together mean steep ground. Wide spacing means gentler ground and usually an easier walk.

2. Find ridges and valleys

Contour lines form a V that points uphill in a valley and downhill on a ridge. Ridges can offer dry travel and visibility; valleys often collect water and thicker cover.

3. Look for saddles

A saddle is a lower pass between two higher points. On a contour map it looks like an hourglass or a shallow dip in a ridge.

4. Notice benches

A bench is a flatter shelf on a slope, shown by contours briefly spreading apart. It can make a practical route or a natural transition area.

5. Plan the walk

Trace your route across—not straight up—closely packed contours. Check distance, daylight, weather, property status, and legal access before leaving the road.

Use it on the map

Turn on “Contour lines” under Terrain and access, then zoom in until the details appear. Pair it with forest access roads to understand where a route begins—never as confirmation that a road is open or that entry is permitted.

Open contour example