The Hilltop is 1130 Feet in Elevation
To find the Spot Elevation of a hilltop, add 1/2 the contour interval to the next lower counter line - or - subtract 1/2 the contour interval to the next higher contour line.
In the above picture, there is 500 feet of elevation between the 700 foot level and 1200 foot level. Therefore, there is 100 feet of elevation between Index Contour Lines (the dark, thick lines), and therefore 20 feet of elevation between Contour Lines (the thin, lighter lines). 20 feet is the Contour Interval.
As can be seen, from the 1100 foot Index Contour Line, there is one additional contour line before the hilltop (1120 feet). Adding 1/2 the contour interval (20 / 2 = 10), or 10 feet to 1120 makes the elevation of the hilltop 1130 feet.
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