Earth.com

Adventurers and hikers can now download the new USGS topographic maps for free

The USGS publishes free topographic maps that show trails, rivers, and campsites in great detail for hikers, cyclists, and ...
insider.si.edu

Map reading for aviators, with a chapter on aerial navigation, by C.B. Benson

https://siris-libraries.si.edu/ipac20/ipac.jsp?&profile=liball&source=~!silibraries&uri=full=3100001~!161279~!0#focus ...