As climbers we all know the importance of knowing our way in the outdoors. Maps, especially topographic maps, are one of our essential guides. They allow us to plan trips, inform us of our surroundings, and help to guide us when we are lost. Traditionally we use printed topo maps. These are often made of paper or a weather resistant material.

Over the past few years, digital mapping products have gained in popularity. They offer greater flexibility and functionality than traditional maps. The United States Geological Survey is the root source of many of these products. Using the same data as traditional USGS printed maps, they provide electronic versions in various formats. These may be obtained directly from the USGS or through third party companies that provide added value.

Topo Maps online
The simplest form of digital map is an electronic version of the standard USGS topo maps. They call these Digital Raster Graphics, or DRGs for short. They are scanned images of the standard topo maps, including all of the collar information. They are offered in three basic scales 1:24,000, 1:100,000, and 1:250,000-scale, although other scales do exist. The 1:24,000 scale maps correspond to the 7.5-minute quadrangles most of us are familiar with.

DRG maps are made available on the GIS Data Depot website. This site allows you to locate and download the maps you require. Alternatively, you can select several maps and have them written to a CD and mailed to you. However, there is a charge for this.

The maps provided for download are ZIP files containing the scanned map in TIFF format (a common image file format) and additional files containing information on the map. The TIFF file can be viewed using most common graphics programs. Using these maps and a graphics program, you can do many things with the map such as crop it, print it, compose several maps into one, etc. This is very useful for areas such as Mt. Rainier which our printed on two separate USGA quads. For example, in this case you can combine the image of both maps and print just the area you require. Using a traditional USGS topo you would have to carry two maps (or get creative with scissors and tape!).

Another way to obtain topo maps is to use one of the online mapping websites. TopoZone.com is a free service on the web. One of the advantages of TopoZone.com is that it provides an easy interface for searching, displaying, and printing maps. No additional software beyond your web browser is required. The website offers information and instructions for using their product.

Maptech offers an online tool called MapServer. This website offers better quality maps, but I find the interface harder to use.

Commercial Products
Digital mapping products offer some features beyond traditional maps; however, the real advantages come with custom software applications. Programs such as "Topo!" from National Geographic Maps provide advanced features such as advanced searching, customized printing, seamless coverage, and 3D digital shading. Delorme, Maptech, and others offer similar products.

Personally I use the Topo! product and have had great success. They offer "Topo! Washington" which provides complete coverage for the state of Washington. The quality of maps that I have printed is outstanding. It offers complete customization of printing parameters; however, I have found that the default values yield the best results. I have found that using Legal sized paper yields a decent sized map for most uses.

The only downside I have experienced is when the maps get wet. Since I have an ink-jet printer, the printouts get smudged easily when wet. Several companies offer weather resistant paper to avoid this problem but I have not tried them. Generally I just fold the map and keep it protected in a zippered plastic bag. Alternatively, you can avoid smeared maps by printing them out on a laser printer.

Most of the commercial products also offer GPS compatibility. This allows for the import and export of data with a GPS unit. You can use the software to mark you trip's waypoints and then upload them to the GPS. In the field you can use the GPS to navigate based on these points. This is especially useful in a whiteout. You can also do the reverse, use your GPS to mark waypoints field and then export them to the mapping software. This allows you to see your route on the map. I often use this in areas where the trails are not marked on the USGS maps.

Conclusion
As you can see, digital topo maps provide advantages over traditional printed maps. This is especially true when combined with customized software. The best way to become familiar with them is to spend some time using them. A list of links is provided in the sidebar. These sites offer a good starting point offering instructions and additional information.