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Digital Mapping for Distance Hikers

by Dave Porter

I admit it. I am an unrepentant cartophile, worthy of a twelve-step program. I’d rather sit down and read a map than any book you can name. A vicarious vice beyond shame, maps and mapping obsess me; therefore, the digital age enthralls me and quickly I discovered digital maps.

Although digital mapping is not for everyone, there are a few special circumstances, somewhat unique to distance hikers which can justify the modest expense which might be incurred.It is quite clear to experienced distance hikers that both the AT and PCT are not in need of further mapping, at least as regards completeness and convenience on trail.The guidebooks and available maps are quite adequate for a thru-hike, but when route-finding or an alternate route is necessary there are now products available which can be of significant help, if not just plain fun. This is not a thorough product review of all available resources, rather it is an attempt to demonstrate the utility of digital mapping for trip planning on long distance routes which are not (yet) available. Also, since the USGS has, in its’ wisdom, virtually done away with the 1:64,000 (15 minute) quadrangles not only do we walk across two to three 7.5 minute quads each day; but they are bulky and expensive if one wishes to do a distance hike, much less carry with you a bunch of maps (even if you trim them down to save weight).The ability to print out high quality maps from all of the following is a big plus, customizing the area, adding waypoints as desired and printing them out at home (color or black and white) or at a local print shop - i.e. Kinkos, etc.

The Appalachian Trail is covered in a series of 4 CDs at $39 each or full set for $139 from Maptech, Greenland, NH. These are raster images of USGS topographic quadrangles with the AT overlayed on them.They could be useful in alternate route planning. Maptech also has a series available for each state, but from our distance hiking perspective neither Montana nor Wyoming are currently available, therefore limiting their utility for the CDT. The PCT is well covered with the state series.

Wildflower Productions, San Francisco, CAproduces a series of interactive maps on CD-ROM called TOPO! which are of excellent quality and good functionality (usually at $49.95). There is complete coverage of the AT except for a short segment in Pennsylvania and a short break in Virginia. The CDT area is less well covered at present, with Wyoming, Montana and new Mexico still not available, but due in 6 - 12 months. The PCT is well covered through multiple products. Their recent release of full state CD-ROMS of all California is now available, but at a significant price of $199. If I was not so impressed with the quality and functionality of their product I would whine a lot more about this.You can estimate the price for other states and regions based on the size of California (i.e. - all six New England states also at $199) Wildflower Productions maintains a web site , TOPO!Trails, (see below) upon which are many intriguing hiking route overlays which have been submitted by users and are fun to download. A very useful separate (from the individual regional CDs) is TOPO!GPS which functions with all of the regional CDs and allows GPS uploading and downloading of waypoints.

DeLorme of Yarmouth, ME,has a product which is uniquely functional (and affordable at $99) for the distance hiker. It is called TopoUSA (ver 2.0) and is comprised of vector-based (rather than raster-based) maps not unlike those in their well-known gazeteer series.It is important that I am reviewing ver. 2.0 since it is a very significant upgrade from the previous version. It is comprised of six CD-ROMs dividing the USA into six regions including Alaska and Hawaii.The functionality of the program equals the previous two with a significant added feature.With this addition, the distance hiker can look over a very large area in one 3-D view which can be rotated 360 degrees and viewed from any verticle angle. At first this looks like a gimmick, but as I was plotting a CDT route through New Mexico, itwas amazing to see a proposed route in 3-D, look it over carefully from all angles, and ‘zoom in’, ‘zoom out’ seamlessly with included shaded relief.Although these are vector based maps they print out very well.You can add as many alternative routes as you wish as well as waypoints for GPS use.The only deficiency I’ve identified is the inability to choose UTM rather than Lat/Long as that choice does exist in the previous two products. They have another product called 3-D TopoQuads, which contains the same functionality but in addition contains rasterized images of all of the 7.5 degree USGS quads. Although this adds greater detail, this comes at a big increase in price (understandable, since the size of such files is immense) and a marked increase in the number of CDs necessary to cover a similar area. They are not, therefore, as usable for distance hikers.

It must be emphasized thateach of these products allows both up-loading and down-loading waypoints with most of the common GPS units available. My son has done this extensively with the TOPO! (Wildflower Productions) CDs and with TopoUSA and he has found it to be very useful.

The difference between a vector-based graphic and a raster-based graphic is important.Vector graphics are based on points with values and calculable features such as curves, lines, distances, angles, etc. and do not degrade significantly with enlargement, but lack the detail of ‘rasterized USGS quads to a great degree. Raster based images are exact replications of scanned images and is pixel based, suchthat they contain all of the original image of a USGs quad but will loose some of the clarity upon enlargement. The importance of this to the distance hiker becomes apparent when one ‘zooms-in’ on the map, particularly in a trail town where in the DeLorme vector images every street is named, whereas in the raster-based images of TOPO! and Maptech’s Terrain Navigator series, contain only the information from the original USGS quads and therefore does not (usually) contain streetnames. In this same vein, the presence and accuracy of trails identified on the two varieties also is at issue. TopoUSA has many trails, but in those regions with which I am most familiar, many are not identified.As we all know, the USGS quads also don’t have all of the trails and/or sometimes misplace them.Therefore, one can not rely on any of these products for all trail-related issues; but all are useful in planning a long distance hike. The thru-hiker will be particularly well-served by TopoUSA, whereas the section hiker will be well-served by any of them.

The functionality referred to above includes for each:

• Add (draw) routes (in different colors) on each, save and print routes.

• Add waypoints for compass or GPS use.

• Add notes directly to the map.

• Add symbols (i.e. - flags, hikers, campgrounds, etc.).

• Draw/printtrail elevation profiles, elevation gain/loss.

• Measure mileage, linear and slope compensated.

A word of warning: As regards distance measurements, with each of the products described, there is an error of between 10% -15% in underestimatingroute distances.This can be improved slightly by adding your routes and waypoints at the very highest magnification the program allows, thereby allowing greater accuracy in locating the route.Straight line distance measurements are very accurate. Conversely, gross elevation gain/loss is overestimated. Net elevation gains are more accurate.

Each of the above products has a useful web site for previewing the products and identifying the areas of coverage of each CD-ROM.

• www.DeLorme.com

• www.maptech.com

• www.topo.com & www.topo.com/trails

I have not had the opportunity to review products coveringCanadian distance hiking trails, but software does exist from Fugawi and Navitrak . Map Academy also has a series which cover areas useful to distance hikers but I have not had an opportunity to review them either.These can be found on-line at adventuroustraveler.com.