Oh, and, um, you don't need steel for gun barrels or lead for ammo. You'd be amazed what rope wrapped around hollowed-out logs pushing rocks out the...
Did you try contacting the author(s) of the papers? In my experience, most authors are happy to hear about uses of their work (even if they are in a...
There are lots of tools out there that can do hillshading on available DEMs. QGIS is one option. A reasonable dataset for maps of the US is ETOPO2.
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