Wilderness Navigation: Finding Your Way Using Map, Compass, Altimeter & GPS

by Bob Burns

Flat areas: No contour lines at all. Gentle slopes: Widely spaced contour lines. Steep slopes: Closely spaced contour lines. Cliffs: Contour lines extremely close together or even touching. Valleys, ravines, gullies, and couloirs: Contour lines in a pattern of Us for gentle, rounded valleys or gullies; Vs for sharp valleys and gullies. The Us and Vs point uphill, in the direction of higher elevation. Ridges or spurs: Contour lines in a pattern of Us for gentle, rounded ridges; Vs for sharp ridges. The Us and Vs point downhill, in the direction of lower elevation. Peaks or summits: A concentric pattern of contour lines, with the summit being the innermost and highest ring. Peaks are also often indicated by Xs, elevations, benchmarks (BMs), or triangle symbols. Cirques or bowls: Patterns of contour lines forming at least a semicircle, rising from a low spot in the center to form a natural amphitheater at the head of a valley. Saddles, passes, or cols: An hourglass shape (with higher contour lines on two sides), indicating a low point on a ridge.