Maps help us find, discover, and reach new places. Although the field of geography is focused on locations, it is also a discipline of time. And maps are a great way to step back in time to see how places, features, and even the ways cartographers design maps, have changed over the years.
Using scanned maps and data from the United States Geological Survey (USGS), Esri developed an interactive tool to explore topographic maps of the US. The Historical Topo Map Explorer allows users to simply click a spot on a zoomable map and get instant access to topographic maps going back several decades.
Founded in 1879, the USGS published their first topographic map in 1882. The agency focused itself on implementing a standardized map production system, allowing maps to be created consistently across multiple areas at a scale of 1:24,000. In 1947 USGS cartographers began mapping the entire conterminous United States using this system.
Today, more than 180,000 topographic maps are now in the USGS’s online archive, including an expanded range of map scales going from 1:24,000 to 1:250,000. Each of these maps, now digitally scanned and georeferenced, is freely available through the USGS. And tools like this one are a fantastic way to browse this massive library of maps
Maps are often used to help us know where we’re going. But this application offers a terrific opportunity to get lost in the beauty of topographic maps, the geography of the United States, and an experience that makes both a joy to explore.
