So, you have decided you want to look at topographic maps on your own computer and are wondering how to get started.
There are a number of online services that make this pretty easy if you have a decent internet connection.
TopoZone used to be my favorite on-line resource. However, as of summer 2008, topozone is part of trails.com and they have made it all but a teaser unless you have a paid subscription, for 50 bucks a year.
Even this won't do however, if you want the maps on a laptop to carry into the field. You can purchase data on CD or DVD from many vendors, perhaps packaged with a viewing program. (The software is really what you are paying for, since the maps themselves were already paid for by your tax dollars, maybe years ago by your parents tax dollars.)
The US Geological Survey, who you might think would make this kind of thing available to the public, instead provides private sector outfits with data and forces you to deal with them. You can view this as outsourcing or conspiracy as you see fit.
I use the NGS topo! maps myself and am quite happy with them. At the most detailed level, these provided digitized copy of the USGS 1:24,000 scale 7.5 minute map series. I no longer use their TOPO! software, but have written my own viewer, called gtopo. If you have TOPO! map sets and run linux, you should download it and try it out as it is open source (free) software.
The NGS TOPO! web site is pretty bad, but their scanned maps, especially using my viewer, are nice.
A great source of both maps are air photos is the Terraserver site run by microsoft. Terraserver-usa.com is the site you want (plain old Terraserver.com is an entirely different commerical site). For more information about all this, see my Terraserver notes.
The commercial situation with regard to free USGS map availability
may have changed as of late 2006. The claim is that you can download
any USGS topo map as a TIFF image, with thanks at least in part due
to google earth.
See USGS quads as a possible
source of more information. I have yet to get anywhere with this,
so view this as unconfirmed rumor.
You can find DRG (digital raster graphics) data here and there on
the internet, and CD's are sold on the internet (such as Ebay).
It seems that this data is more or less in the public domain and
it is not illegal to copy, trade, and sell (or even give away)
this information. But I am no lawyer, so don't quote me on this,
but it does make sense, your tax dollars paid for this.
Check out
Stu Olson
who sells DVD's for Arizona and Utah.
This site has maps of Utah: Utah water rights
This site has maps of California: California in GeoTiff format
ATDI offers free DEM (Digital Elevation Model) data, but apparently gets snippy if you hit their website too hard. ATDI DEM data
The USGS has completed the job of digitizing the maps for all 50 states and licenses this data to various companies. The national Geographic Society has redone this task, claiming better accuracy and resolution. The estimate is that there are 60,000 maps that have been digitized. The NGS product costs about $100 per state (therein lies the rub), but another option is to visit a "map kiosk" (if you can find one), which some outdoor shops like REI or LL Bean are said to have. There you can print a 13x18 inch map for $8.00 (as compared to $6.00 for a printed USGS map).
Another option is to visit Offroute.com where you can browse the NGS dataset and order printed maps (you usually get them in 3 days). There are 3 sizes:
MyTopo.com offers a service similar to offroute, but cheaper, and with a more awkward interface.
The forward thinking State of Montana makes a collection of DRG maps of the entire state available to the public as part of their exemplary natural resource information system.
Uncle Tom's Computer Info / tom@mmto.org