Using Topographic Maps

Topographic maps are elaborated by the Geological Survey of the Department of Interior can be bought in many establishments that sell sports gear and are near the area in which one is interested.

Likewise, they are accessible through the Internet along with a variety of different map software programs that can be bought in the market. The purpose of topographic maps is show the characteristics of the surface covering certain area, including mountains, valleys, hills, lakes, rivers, creeks, bridges, highways, path, etc. This is only achieved with the use of “contour lines” that show in feet the elevation under or above the sea level.

All the points in a contour line have a same elevation. To make this elevation be easy to find in a topographic map, every fifth line is generally drawn and highlighted from the others with its numbered elevation. Each contour line generally indicates a change of 50 feet in altitude.

When reading a topographic map one can observe the different degrees slope in the various hills, mountains, creeks and rivers of the area of interest. Where the contour lines join, indicates that the degree of the fall in that locality is steeper than the areas in which the contour lines are more separated. So in this way a topographic map can offer a general aerial overview of the extension of land of a specific area.

Topographic maps include various roads and paths in the area. At observing and the elevation changes one can have a good idea of the accessibility to a determined place. These maps also show where the great tailing piles of large scale old mining lie. This is an index of where large scale mining operations happened, as well as old bucket line dredges that sometimes processed thousand of yards of material per day.