what does this symbol mean?

Topographic map symbols

What the contour lines, benchmarks, north arrows, scale bars and other symbols on a USGS topographic map mean, with the Ordnance Survey’s versions beside them.

Test yourself: Topographic map symbols quiz

Relief and height 4 symbols

Direction and distance 2 symbols

Routes and lines 3 symbols

Water and land 2 symbols

Buildings and sites 3 symbols

About topographic map symbols

A topographic map shows the shape of the land with contour lines, and everything on it, from streams to buildings, with a standard set of symbols. These pages describe what each symbol on a US Geological Survey topographic map shows, from the USGS’s own symbol sheet, with the versions used by Natural Resources Canada and the Ordnance Survey in Britain where they differ. The map’s own legend says what its symbols mean; the USGS says most of the symbols on its maps from 1947 to 2009 are still in use.

Colours

The USGS sorts its symbols by colour: brown for contour lines, blue for lakes, streams and other water, green for vegetation, red for land grids and important roads, and black for other roads and trails, railroads, boundaries and other cultural features. Purple was once used to show changes on revised maps and is still on many older sheets.

Relief and height

Contours join points of equal elevation; the wider index contours carry the height. Contours with ticks on the downhill side are depression contours. BM marks a benchmark, a permanent survey mark with a measured elevation, and a small cross with a number a spot elevation.

Direction and distance

The margin carries the north arrows, a star for true north, GN for grid north and MN for magnetic north, and the scale bar. On the USGS 7.5-minute maps the scale is 1:24,000, so an inch on the map is 2,000 feet on the ground.

Lines, water and buildings

A black dashed line is a trail; a line with cross ticks a railroad; a line with dots a power line. A blue line of dashes and dots is an intermittent stream, and blue tufts a marsh. Small black squares are buildings, a dashed outline with Cem a cemetery, and crossed picks a quarry or open pit mine.

Sources

  1. Topographic Map Symbols, USGS General Information Product (first posted 2005), U.S. Geological Survey, Reading Topographic Maps
  2. Where can I find a topographic map symbol sheet?, USGS FAQ, U.S. Geological Survey, FAQ answer
  3. What do the different north arrows on a USGS topographic map mean?, USGS FAQ, U.S. Geological Survey, FAQ answer
  4. Finding Your Way with Map and Compass, USGS Fact Sheet 035-01, March 2001, U.S. Geological Survey, From near to far: distance
  5. Hachured contour, GIS Dictionary, Esri, Definition
  6. Specifications to Support Classification, Standards of Accuracy, and General Specifications of Geodetic Control Surveys: Geodetic Bench Marks, NOAA Manual NOS NGS 1, Foreword, NOAA National Geodetic Survey, Foreword
  7. Topographic Maps: The Basics, Centre for Topographic Information guide, Natural Resources Canada, What do the colours mean?
  8. Map reading: from the beginner to the advanced map reader, Ordnance Survey leaflet, Ordnance Survey, The basics

Researched, edited and approved by Rory Hansen before publishing. Last reviewed October 9, 2026. How we research