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Pink water on topo maps

January 11 2012 | 0 comments
Categories: Map Data

Why is the water pink on some topo map tiles? I'm streaming topos from Esri, in one tile on the north water is blue but in the tile below it is pink.

Mapping Center Answer:

This stumped me, too, at first because I know that pink is not used on USGS maps. However, I learned that the map was originally printed with purple ink, not pink. So on this quad you will see hydrographic features (swamps, intermittent lakes, perennial lakes), roads, highways, buildings and even an airport in purple ink. From this online USGS document, Topographic Map Symbols, you can read:

At one time, purple was used as a revision color to show all feature changes. Currently, purple is not used in our revision program, but purple features are still present on many existing maps.

I also noted at the end of the document that you can all USGS to ask about their maps,. So I called 1-888-ASK-USGS and, after choosing option 2, I was immediately connected to as mapping specialist who confirmed for me that this was the case for the map in question, the Stanley SE quad. He read to me from the bottom of the original map:

Purple revisions shown in purple and woodland compiled from aerial photography taken in 1976 and 1979. Map edited 1981. This information not field checked.

This was the first I learned about the excellent USGS hotline, 1-888-ASK-USGS. If you have further questions about USGS topographic maps, I strongly urge you to contact them through this hotline!

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