The free topographic maps that you can search and print at CascadeGear.com are built using USGS maps utilizing Google's Maps functionality. The data is provided by the USGS geospacial data and includes hundreds of thousands of significant features such as lakes, streams, AND over 10,000 trails across the United States.
The Libre Project is another great source for images of full USGS & totally free topographic maps.We want to make this as useful as possible so please provide feedback.