Switchback Ledger

Read the
shape of
the land.

Find the climb, trace the creek, and read what the lines on a topographic map tell you before you head out.

Learn the contour lines
Illustrative contour map with a stream flowing south. Contours bend north and point upstream where they meet the stream. A dotted route climbs from point A to point B.
Practice map · imaginary terrainContour interval · 40 ft

What the lines tell you

Elevation
A contour joins points at the same elevation. The contour interval tells you the change in elevation from one line to the next. Look for the interval and its units in the map margin.
Slope
On the same map, closely spaced contours mark a steeper slope. Widely spaced lines mark gentler terrain. Compare the spacing where your route actually crosses the lines.
Stream valleys
Where contours cross a stream, the bends point upstream. In the practice map, the stream flows south while the contour bends point north.

Trace A to B

Point A sits on the 1,200-foot line. The dotted route climbs through three 40-foot intervals to point B. What elevation does it reach?

Show the elevation

1,320 feet. The route crosses 1,240 and 1,280 feet before arriving at 1,320 feet, for a gain of 120 feet on this climb.

Before you use a real map