I have had many requests over the years to add a USGS topographic Map overlay without the map borders. This is a huge project and I have finally decided to move forward with it.
You can read more about this project below, or skip right to the store and purchase them.
Update 11/28/2011 Seamless Topo Maps – I have released a seamless version (without the map borders) version of the USGS Topographic Map layer for Google Earth. In addition to removing the map borders, hill shading has been added using the 10-meter National Elevation Dataset (NED), which greatly enhances the topography and makes it [...]