Recently, I wrote about a wonderful new resource called the USGS Historical Map Explorer, which provides an easy way to examine change over time using USGS maps for any area of the USA. But let’s say you want to add these historical maps to other data layers that you are investigating in ArcGIS Online. The way to accomplish this is via the method that my colleague Charlie Fitzpatrick recently described–by using the Esri Map Layers through your ArcGIS Online organizational subscription.
To access these maps, use the Add Data function and Browse Esri Map Layers. Select Basemaps, and then Historical Maps, as shown below.
I selected the 1:24,000 scale USGS layer and zoomed to Morrison, Colorado, as shown below.
The most current USGS maps are available through the “USA Topo” layer. I searched for this layer in ArcGIS Online and added it, as shown below:
But as this “most current” map is from 1995, you have yet another option: You can compare all of these USGS maps to the up-to-date topographic basemap in ArcGIS Online, which is no more than a few months old. At your fingertips you now have a wonderful library of tens of thousands of historical USGS topographic maps and current basemaps with which you can study physical and cultural changes on the landscape. You can also do this with the historical USGS topographic map explorer that I previously wrote about.
Each of these two methods has its advantages. The USGS topographic map explorer is an app, and like all apps, it does only a few things, but it does them very well. It is best if all you want to do is investigate land use change over time with historical maps. The method that this blog focuses on–accessing the historical maps via ArcGIS Online’s Esri map layers–gives you much more flexibility and power. Using this method, you can add other layers to your investigation, such as historical aerial photographs, population change, zoning, watersheds, and much more.