Maps are an important tool in building preparedness plans. Knowing the terrain around you will help you find resources and the fastest way to your retreat site. Good maps are also a part of planning for camping trips, hikes and other outdoor activities. Obtaining a collection of maps can be a bit expensive.
National Geographic has stepped up with a free service that we should all know about. Their website is offering downloadable PDF files of maps from the United States Geological Survey. These maps are topographical that show topographical features, water sources, highway details, and political boundaries. Each PDF file has 5 pages. The first is the whole quad and the following four are one quarter of the area showing greater detail. Each of the pages are sized to print on standard 8.5" x 11" printer paper and are full color. They also have all of the legend information such as declination and scale that you would expect on this kind of map.
Today's technology provides a number of options to use these maps. The cost of home printers is a low as they have ever been and the choices in tablet devices at affordable prices allows you carry all of the maps that you might need for an entire trip.
If you are looking for a good source of topo maps you should check out National Geographic's website.