Ever wonder what those squiggly brown lines are on a hiking map? Contour lines depict the shape and elevation of the terrain, including the steepness of the trail and height of the mountain. They are a dominant symbol on topographic, or topo, maps. Hikers are familiar with the standard “quad” topo map from the US Geological Survey (USGS) which shows elevation, water bodies and other land features.
The big news in the hiking world is that the USGS will no longer be printing topographic maps on a regular basis. The new generation of national topographic maps, called US Topo, is now available electronically.
These maps can be manipulated online, but printing a map on a personal printer leaves a lot to be desired. To get a print copy of the standard sized topo map, you will have to download a file and pay to have it printed at a commercial printing establishment, or you can order a copy from the USGS.
An outstanding feature of US Topo is that the historical quadrangles are being digitized. For example, you can now view online all of the topo maps of Seattle from 1893 to current day!
The Seattle Public Library is cooperating with the USGS to offer a “first of its kind” class to introduce you to the world of electronic mapping, and specifically to the use of the online US Topo. The presenter is Tom Carlson, a geographer who is the Washington State Liaison to the USGS.
Classes will be held at four branches and the Central Library in October and November. Check the library’s online calendar for more information; type “US Topo” in the search box to see the class listings.
Be sure to check out the topographic map display on Level 9 of the Central Seattle Public Library during the month of October.