You know, there are some really nifty earth-science resources on the old internets that serve as bright spots in the otherwise nihilistic cyberscape of porn, L33T-speak, and rickrolling that makes up the bulk of the greatest communication tool ever devised by humans. Now, I might be behind the times on these things - being a neo-luddite - but I have recently made the acquaintance of a the online component of the BLM's and National Forest Service's "National Integrated Land System", called Geocommunicator.
It's a pretty handy set of online maps for most of the U.S., complete with a faux-GIS interface that lets you put different layers onto different base-maps, annotate the maps, and the nab pdf versions of the maps for quick and easy printing. According to their "About" Page, the Geocommunicator provides a central point for clearing geospatial data related to Land and Mineral Use, Federal Land Stewardship, and Land Survey Information.
You can use a topo map, a road map, or an aerial view as your base layer, and then populate it with all sorts of information. For me, at least, the most practical maps available are the Land Use Maps; these allow you to quickly and easily scope-out where you'll have easy access to outcrops (i.e., BLM land) versus where you'll get a free ticket to some CIA-run torture camp in Uzbekistan (i.e., DoD administered land). The picture below is a grab from one of the maps I made, showing the checkerboard of SW Wyoming and all the sweet, sweet BLM land there is to wander around on.
With some planning ahead of time, you could just print out the needed maps, instead of having to haul the "Lowley Worm's Biggest Day in the Field Ever" -sized Gazeteers around with you everywhere. It's a pretty handy little tool for field work, and it's free (or rather, you've already paid for it by paying your taxes).