Post History
The USGS Fort Collins Science Center published the following map of the conterminous United States in 2005: It has been published as a factsheet with a PDF (that can be zoomed for more detail): ...
Answer
The USGS Fort Collins Science Center published the following map of the conterminous United States in 2005: It has been published as a factsheet with a PDF (that can be zoomed for more detail): ...