Color is the fastest way to read a USGS topo map. Before you know a single symbol, the colors tell you what kind of feature you're looking at: brown for the shape of the land, blue for water, green for woods, black and red for things people built or surveyed, and purple for changes added after the map was first printed.
What do the colors on a topo map mean?
Brown: contour lines and elevation. Blue: water. Green: woodland. White: open land. Black: buildings, roads, trails, boundaries, and names. Red: major roads, survey lines, and recreation symbols. Purple: revisions from aerial photos. Gray or pink: built-up areas.
IN THIS GUIDE
Brown: the shape of the land · Blue: water · Green: woodland · Black: man-made features and names · Red: major roads, survey lines, and recreation · Purple: revisions · Gray or pink tint: built-up areas · Reading a map by color · FAQ
Brown: the shape of the land
Brown shows relief. Contour lines connect points of equal elevation, so their spacing tells you how steep the ground is.
Index contour
A heavier brown line labeled with its elevation, usually every fifth contour.
Depression contour
Brown contours with ticks pointing inward mark a hollow, sinkhole, or crater.
Blue: water
Everything wet is blue: streams, lakes, springs, marshes, and even glaciers and permanent snowfields.
Perennial stream
A solid blue line marks a stream that flows year-round.
Marsh or swamp
Blue tufts of grass mark wet ground.
Glacier
On glaciers and permanent snowfields, the contours themselves turn blue.
Green: woodland
Green marks trees and dense brush. White, the absence of green, means open or lightly vegetated land.
Woodland
A solid light green tint covers forest.
Orchard
Green patterns mark orchards, vineyards, and scrub.
Black: man-made features and names
Most things people build are black, along with most names and labels.
Buildings
Small black squares mark individual buildings. Larger ones are drawn to shape.
Trail
Minor roads, trails, and railroads are black lines.
Spot elevation
Black numbers give elevations at summits, junctions, and benchmarks.
Red: major roads, survey lines, and recreation
Red picks out the features you most want to find quickly.
Primary highway
Major roads are filled in red. Secondary highways are red and white.
Section line
Thin red lines mark township, range, and section lines in Public Land Survey states.
Campground
Campgrounds and picnic areas get red icons. Some maps use the small black version shown beside it.
Purple: revisions
On many older USGS quads, especially those revised in the 1970s and 1980s, you'll see roads, buildings, and reservoirs printed in purple. Those features were added from aerial photographs without a full field check. USGS has since stopped using purple, but a lot of maps still in use carry it. Purple marks what changed since the original survey, often new subdivisions, highways, and lakes.
Gray or pink tint: built-up areas
In towns and cities, the map stops drawing every building and uses a tint instead.
Built-up area
A gray tint on newer maps, or a pink tint on older ones, covers built-up areas. Only landmark buildings like schools and churches are shown.
WATCH
Topo Map Reading, part 6: Map Symbols
Contour lines, benchmarks, rivers, streams, lakes, swamps, roads, trails, buildings, and campgrounds in under a minute.
Watch the full Topo Map Reading series →Reading a map by color
- Start with brown and blue. Contours and streams together show you the ridges and valleys.
- Use green for route-finding. Forest edges and clearings are easy to spot on the ground.
- Note the map's date. Purple overprints and old vegetation tell you how much may have changed.
- Check the margin. Every USGS quad lists its survey and revision dates, plus the contour interval.
PUT IT TO USE
See these colors on a real map
Frequently asked questions
What does purple mean on a topo map?
Purple marks revisions added from aerial photos, without full field checking, on older USGS maps. It usually shows roads, buildings, and lakes built after the original survey.
Why are some roads red and others black?
Red is used for primary and secondary highways so they stand out. Light-duty roads, unimproved roads, and trails are black.
What does white mean on a topo map?
White means open or lightly vegetated land: fields, meadows, grassland, desert, or rock.
Why are glacier contours blue?
Glaciers and permanent snowfields are water features, so USGS draws their contours in blue instead of brown.
MORE SYMBOL GUIDES
Contour Lines on Topo Maps: Index, Intermediate & Depression Contours · Water Symbols on Topo Maps: Streams, Lakes, Springs & Wetlands · Vegetation & Surface Symbols: What Green Means on a Topo Map
← Back to all USGS map symbols
Symbol artwork from the U.S. Geological Survey Topographic Map Symbols brochure (public domain).