Find a location on the map, and note its color.
Find the same color on the map key.
Read the numbers near the top and bottom of the color bar. These are the upper and lower elevation limits for that color. Your location is somewhere between these two elevations.
Find a location on the map.
Read the map legend to see how many feet or meters are represented by each contour line.
Find the first major contour line below your location that has a number printed along it. Remember this number.
Count the number of contour lines between the labeled contour and your location.
Multiply the number of contour lines by the number of feet or meters represented by each line. Add this number to the elevation of the labeled contour. This gives you the lower limit of your location elevation.
Add the value of one contour line to determine location upper limit. The location true elevation is somewhere between the upper and lower limits.