Sketch 40 foot long interval contour lines using specific site elevations given. you must interpolate elevations between known values. the coastline is datum- mean sea level. begin your work at the coast and work inland. circle elevations from 0-40 feet in green, 41-80 feet in yellow, etc. then when drawing the contour lines, you will be grouping the colors, with the contour lines as separators between the color groups.