Laura Bliss is CityLab’s west coast bureau chief. She also authors MapLab, a biweekly newsletter about maps (subscribe here). Her work has appeared in the New York Times, The Atlantic, Los Angeles magazine, and beyond.
A new open-access tool from the U.S. Geological Survey lets you browse maps of any place, time, or scale.
The cartography arm of the U.S. Geological Survey has been on an open-access roll. First they send their constantly updating stream of satellite imagery to what's basically a public dropbox, so that anyone can use Landsat-8 photographs for free. And now they're introducing topoView, an online archival tool that makes truly accessible the agency's 178,000 topographical maps, dating from 1880 (shortly after the USGS started mapping the country) to 2010.
You could always get USGS maps by buying them in print or, as of 2011, by downloading digital images with the clunky text-query engine on their site. But that required a lot of guesswork, as Greg Miller at Wired laments:
It involved a lot of clicking on what you hoped was the right thing, squinting at the tiny preview maps, and twiddling your thumbs while the enormous full-sized version downloaded. And then starting over when it turned out to be the wrong thing.
topoView lets you search for maps by using a map of the United States. Start by entering a location into the search box, and the map will guide you to that place. Then you'll see a layers of different pastel colors fill the map in patches. Those colors represent the different scales for which maps of the region are available: 1:24,000 (the most zoomed-in you can get) is pink, 1:48,000 is chartreuse, and so on. The key to these scales, which can also be used as a filter, can be found in the lower right hand corner. Choose a scale.
Eventually, a label will pop up and a black line will encircle your searched-for place. Click, and a box showing all the maps available at that scale will appear in the lower left-hand corner. The files to all of those maps are right there, too, ready to be previewed or downloaded to your heart's content.
And, perhaps best of all, you can easily adjust the date range you're searching within by zipping the two dots on the bar at the top of the screen together or apart.
If you're having trouble, it helps to watch the handy explanatory video for clarity. The tool is still slow—there's a lot of data to process, and likely, a lot of users. Even so, this is a level of access and good design that I've rarely seen from a government mapping agency. For all kinds of land-use purposes, the USGS has been mapping the country since 1879. Now, finally, the history that those maps reveal is at the public's patiently drumming fingertips.