No, the Next Generation I refer to is not Star Trek, it is the up-coming USGS digital 1:24 000 topographic maps quads being produced in a staggering 37 layers of detailed digital information! Its like having 37 acetate topo sheets each with a different geographical set of features on it. Wow.

Every USGS 1:24 000 topographic map is currently available in a little-known format called: GeoPDF. Say what? GeoPDF? What the heck is that? Man, these must cost a fortune.

GeoPDF is a spatially-enabled Adobe PDF electronic document that allows the user to turn their mundane Adobe PDF reader software, with a downloadable plug-in, into a nearly fully-featured geographical information system (GIS) able to pump out routes and tracks in a format convertible into popular GPS files. Additionally, PDF reader can perform analytical computations on any GeoPDF USGS quad on your laptop; this computation technology typically reserved, in the past, for expensive GIS software costing tens of thousands of dollars.

Where in the devil would you get such detailed USGS topographic maps of every square kilometer of the USA in this GeoPDF format anyway? And, what pray tell will each topo map cost?

Every USGS quad is available freely at no cost in GeoPDF format. Zoom into your area of interst, and select the PIN tool to stick a virtual pin into the area of the map you want a topographic coverage of, click the PIN's balloon, and select the free product to download. To grab the Geo-PDF plug-in, download it from the maker TerraGo.

Everything is done in Adobe Acrobat Reader. If you don't have Adobe Acrobat Reader 8 or 9, get it free from Adobe. Once the plug-in is installed into Adobe Reader, load the USGS quad, and use the GeoPDF plugin to hotlink a selected point directly to Google Earth (cool!); use it to trace your route to determine distance, bearing, azimuth; and get this, enable it's GPS link when you plug your USB GPS into your laptop (or, desktop) as you travel across the outback in your truck camper to track your progress in real-time

Why download electronic USGS topographic quads when you apparently have them as an extension to your GPS system? Read the fine print on your supplemental GPS software DVD/CD: in almost every instance, your GPS data software will limit you to $40 or $50 dollars worth of USGS and marine navigation and other downloads from your GPS manufacturer's repository. After that you're on your own (i.e. get ready to pay $$$).
Using the GeoPDF system, you have access to every USGS topographic produced for free. Pretty good incentive, eh?

Back to Next Generation. Although the USGS is currently making available their 1st Generation GeoPDF topo maps in hyper-compressed 4000dpi resolution single layer raster (read: scanned) quads, their Next Generation 37 layer upgrade has not been fully generated as yet. This isn't too big a deal, as the raster GeoPDF and TerraGo plugin functionality is still light-years ahead of anything else on the market....and, it's free

To conclude, the 1st users of this GeoPDF technology were the US DOD, and a little-known "Agency" called National Geospatial-Intelligence Agency (don't even ask who they are); now, the USGS and US Forest Service is fully on-board, and kicking out Public Domain maps using it.