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Main Page > Describing Relief in Maps

From the earliest maps to the present, mapmakers have relied on a variety of methods, symbols, and designations to address the challenging task of illustrating the three-dimensional aspects of a location using a flat, two-dimensional map.

AACR2 recognizes many different ways of portraying relief, including

pictorial hachures landform drawing
gradient tints rock drawing form lines
contours spot heights soundings
hypsometric tints bathymetric tints
hill shading satellite imagery

The forms of relief used most often on early North Carolina maps are pictorial, hachures, and soundings. Beginning in the mid to late 19th-century, North Carolina mapmakers began to use additional methods for showing relief, including contours, and spot heights. The examples below show illustrations of each method.


Relief Shown Pictorially

On many early maps of North Carolina and the southeast, topography is illustrated simply by drawings of mountains and hills. Early explorers were clearly aware that there was a large mountain chain several hundred miles to the west of the coast, but the maps they produced show that there was at the time very little additional information.

Detail from "A New and Accurate Map of the Province of North and South Carolina, Georgia, etc.," 1747. NC Archives call number MC.150.1747b.
Detail from "Map of North and South Carolina and Georgia, Constructed from the Latest Authorities," 1827. NC Archives call number MC.150.1827f.

Relief Shown by Hachures

Hachures, defined as "short lines following the direction of maximum slope" (AACR2 Cartographic Materials, 2002) are probably the most common method for showing relief on historic maps of North Carolina. Hachures often designate specific mountains or hills, and are effective at showing variations in elevation, but they still do not convey as much information as numbered relief methods, such as contours and spot heights.

Detail from "A New and Accurate Map of the Province of North and South Carolina, Georgia, etc.," 1747. NC Archives call number MC.150.1747b.
Detail from "Topographical map of the Halsey Mining and Smelting Company's estate, Guilford County, North Carolina," ca. 1854. NCC call number Cm912g H19h.

Depths Shown by Soundings

Soundings are numbers designating the depth of water at a specific place. These appear regularly on very early maps, and were especially important to sailors navigating the treacherous waters off of the Outer Banks. While that area is primarily where soundings are to be found on historic maps of North Carolina, soundings occasionally appear on inland waters.

Detail from "Albemarle Sound, N. Carolina: western part, from the Pasquotank River to the Roanoke and Chowan rivers." NCC call number Cm912m U58a3 1860.
Detail from "A New Map of Carolina Sold by Geo: Willdey at the Great Toy, Spectacle, China-ware and Print Shop, ye Corner of Ludgate Street near St. Pauls London," 1685. NC Archives call number MC.150.1685w.

Relief Shown by Contours

Contour lines designate changes in elevation. Elevation numbers are given at intervals, with the lines appearing concentrically in order to show the changes in elevation in a given area. Contours are not limited to the mountainous western parts of the state, and are often used to show elevation in low-lying areas in the east.

Detail from "Soil map, North Carolina, Gates County sheet," 1929. NC Archives call number MC.041.1929d.

Relief Shown by Spot Heights

Spot heights are simply numbers on or near a location giving the elevation for that place. Some maps use spot heights regularly throughout the area shown, but they are most often used just for large mountains or hills. In many maps of North Carolina, spot heights are given only for the highest peaks (such as Mt. Mitchell and Clingman's Dome).

Detail from "Goldsboro Messenger map of North Carolina,1879: given as a premium to subscribers for 1879." NCC call number Cm912 1879c2.
Detail from "Avery County, North Carolina (State Highway and Public Works Commission)," 1938. NC Archives call number MC.007.1938n.
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