How to Spot Mines on Maps

Open the topographical map. Note the contour lines on the map. All points on a given line are at the same elevation. A tightly-packed series of lines means a steep hill, while lines far apart mean a gentle slope. Blue lines denote streams and rivers while blue patches represent ponds and lakes. Highways are represented by solid lines. The color varies with the type of highway and they will generally be labeled. Examine the map for a dashed line-this will be a county or state border.

Check the map key for two pick-axes crossed with the pick end at the top of the icon. This is the symbol for a quarry or open-pit mine. They may be near large cities or in a rural area, but are rarely near the ocean. Return to the key and identify an upside-down crossed pick-axe image that denotes a gravel, sand, clay or "borrow" pit. They are often filled with water. Look for one near a road as the removed materials are often used in road-bed preparation.

Find a mine entrance by searching for an icon consisting of a straight line with a "Y" fork pointing outward on its right side. Try looking for a mine entrance on your next hike. They may be overgrown and difficult to find.

Go to the NASA website (spaceflight.nasa.gov/gallery/images/station/crew-15/hires/iss015e29867.jpg) for an amazing example of how the Bingham Canyon Mine, the largest open-pit copper mine in the world, can be spotted from the air.