Topographical Map of Stone Mountain

In order to show the topography of Stone Mountain, I inserted various topographical lines at 200 ft intervals. The  red line represents 1600 ft elevation. The orange represents 1400 ft. The yellow represents 1200 ft. The blue represents 1000 ft. I was unable to add a fifth line because the elevation does not go high enough (1800 ft) or low enough (800) ft across the map.