What Are Topographic Maps Used For?

Topographic maps depict both natural and manmade features. They identify such works of nature as valleys, lakes, mountains and vegetation, and manmade structures, including roads, major buildings and boundaries. The distinguishing feature of topographic maps is the use of contour lines to show the shape and elevation of the land. In effect, three-dimensional features of the landscape are shown on a two-dimensional surface.

History

In 1879, the United States Geological Survey (USGS) assumed responsibility for mapping the country and produced its first topographic map.

Uses

Topographic maps are beneficial tools for analyzing the earth's surface, geographic planning and architecture, mining projects and recreational uses, such as camping and fishing.

Techniques

Topographers had to carefully plot maps by hand until the 1940s, when aerial photography was introduced.

Large-Scale Undertaking

From 1879 until 1992, the USGS produced a large-scale topographic map series of the 48 contiguous states and Hawaii. It includes more than 54,000 maps, and identifies almost 2 million natural and manmade features.

Time Frame

Creating an accurate topographic map is a long process. It can take five years from start (identification of map features) to finish (printing).