(Data West Research Agency definition: see GIS glossary.) A map depicting terrain relief showing ground elevation, usually through either contour lines or spot elevations. The map represents the ...

A detailed representation of a landscape, created by the United States Geological Survey, and a rare example of something every bit as beautiful as it is useful. The charts were the brainchild of ...

OFFICIAL large-scale maps are available for comparatively few parts of the world outside western and central Europe, including the British Isles, the eastern United States, India, much of Burma, ...