A couple of days ago, a Google Earth Community member called ‘Forkboy2’ made an awesome post of a network link which will provide access to hundreds of maps on his Topographical Maps Archive web site. These maps were designed for use with Google Earth 4 (like the Rumsey Historical Maps collection) and will load higher resolution data as you zoom in closer (a feature in GE’s KML called Regions). Once you load the network link 
find it under your “Temporary Places” with the label “Topo Map Archive AIO” and turn it on. This will load the contents. Then open the various folders to find the maps you would like to try. Make sure you turn off each map before loading another one so they don’t overlay each other.
The map shown in the screenshot is the “Geologic Map of the US” (which you can load here directly ). One of my favorites is the historical map of the Lewis and Clark Trail which was taken from Lewis’ original map in the early 1800s. Compare the original map to the real Lewis and Clark trail (more detail on this file here). The historical map was pretty accurate considering the lack of modern cartographical tools like GPS and satellites!
There are all kinds of maps included in this collection including topographical maps, aeronautical charts, geological, historical, and even planetary map overlays. Apparently, some or all of these maps were converted for viewing in GE 4 using a software tool called SuperOverlay by Valery Hronusov. This is an excellent collection and I will probably highlight some others in future blog entries. Great work Matt (aka Forkboy2)!
About Frank Taylor
Frank Taylor started the Google Earth Blog in July, 2005 shortly after Google Earth was first released. He has worked with 3D computer graphics and VR for many years and was very impressed with this exciting product. Frank completed a 5.5 year circumnavigation of the earth by sailboat in June 2015 which you can read about at Tahina Expedition, and is a licensed pilot, backpacker, diver, and photographer.
Excellent job but it would be good to mention in the article that it is mostly about USA maps. May seem obvious for someone writing from America but please don’t forget the rest of your audience.
Then again, I wish many national mapping agencies were making their maps as freely available as it seems to be the case in the US…
Here, Here! Its difficult where I live to even buy paper versons of aeronautical charts, so a GoogleEarth version would be really great!
Earth Point is now charging for their township and range “plug in” for Google Earth. Where can I find a free township and range overlay for Google Earth?
I tried to access the maps you mention above “an awesome post of a network link which will provide access to hundreds of maps on his Topographical Maps Archive web site.”, but the link is broken. Do you know have to access this archive?
Thanks,
Wayne