Map Comments
This page contains general comments on the 13 Western United States Maps produced as a complement to my book. Comments are also included on GIS mapmaking software, particularly QGIS, and on available mapping data.
Trails
The National Scenic Trails, (Pacific Crest Trail, Continental Divide Trail, Arizona Trail, and Pacific Northwest Trail), are shown in Red. In Magenta are common CDT alternates, the Grand Enchantment Trail, the Hayduke Trail, the Idaho Centennial Trail, the Colorado Trail, and the John Muir Trail.
Cities Map
For some small resupply towns and outposts I had to use locations I had taken in the field, or I had to find each spot on Google Maps. Most road files did not work well in QGIS. I had to try several before I found one that scaled properly, and did not show roads in the ocean, etcetera. Setting the coordinate system and projection was easy enough, but I suspect there are many other settings I did not know about that would have to be tweaked to make various files work properly. I had wanted to include all of the roads, no matter how minor, that hikers hitch down to access towns. Obviously, some are very minor. I would have to get a very detailed roadmap of the US and then cut out all the minor roads that hikers don't use to end up with maps that make sense. I'm not sure such a detailed file exists, and I'm not sure how I could easily narrow down to the minor roads I want. It's something to learn in the future.
Elevation Map
This map shows that most of the highest ranges in the west are accessed by walking the PCT and CDT. There are several other interesting looking ranges I'll have to visit some day. Two areas are below Sea Level. Death Valley is a very interesting hiking area. Its low elevation is caused by plate tectonics. Imperial Valley includes the Salton Sea. It would be an extension of Mexico's Gulf of California, but the Colorado River deposited enough silt to block the Valley off and it dried up long ago. The river delta in the east of San Francisco Bay is a huge sea level area. I bet kayaking there would be a great way to see a lot of wildlife.
Rock Type Map
The Rock Type Map is a standard geological chart. The trails visit a lot different and interesting geological areas
Siesmic Map
The areas of high siesmic hazard correlate well with volcanic areas and active faults. The trails miss many of the most active parts. I'll have to take side trips sometime to investigate.
Faults, Volcanos, Impact Craters, and Calderas Map
Many of these geological features are clustered along the National Scenic Trails. Still, there are interesting areas I'll have to investigate on other types of trips.
Continental Divide Versus CDT Map
The CDT often strays from the actual continental divide to stay off Indian Land, stay on Public Land, stay near water sources, and stay off difficult high country routes.
Forest Cover Map
Land Cover Map
Ecological Regions Map
The National Scenic Trails tend to the lusher, more vegetated corridors. Lovers of desert life will need to plan other trips to further explore those areas.
Lakes and Rivers Map
The National Scenic Trails tend to ridges and rarely follow significant rivers or large lakes.
Rainfall Map
There is much more precipitation along the PCT and western PNT than along the other trails. Only the PNT samples the Olympic temperate rainforests. There are lush places along the west coast no long trail visits.
Land Management Map
Most of the long stretches of Forest Service Land are already traversed by National Scenic Trails. There are still long stretches to explore off the NSTs.
Designated Wildernesses Map
By hiking the National Scenic Trails, you hit most of the designated wilderness area. There are still long many wildernesses to explore off the NSTs.
A Potentially Interesting Utah Route
The elevation map shows a high elevation band stretching from near the north end of the Arizona trail to the southwest corner of Wyoming. The seismic map also shows this corridor is of above average interest. The Forest Cover Map, the Land Cover Map, and the Ecological Regions Map show this corridor, plus north east Utah and southeast Idaho have fairly lush forests, suggesting the route could connect the Arizona Trail and Yellowstone. Rainfall in the region is highest along this corridor. There is a nearly continuous stretch of Forest Service land in the corridor. There are few designated wildernesses.
GIS Map Making Software Comments
Map Data Source
Most GIS Data used to generate the maps are public domain GIS Shapefiles from NationalAtlas.gov. Locations of some small towns and resupply outposts were taken by me in the field or by zooming in on Google Maps until I could identify the site. Locations of trails were taken by me in the field or from files available on the internet.
QGIS
I used QGIS, a shareware map making application. An expansion was used to make some of the image maps I exported to HTML to make the maps active on my website. QGIS required a long learning curve but enabled me to make these maps. The maps seem quite informative to me and I believe other serious long distance hikers will also benefit. QGIS was also quite useful in examining poorly built GPS files and fixing them by tossing out bad points and forming useable track sections. The benefits I've derived have convinced me that other curious long distance hikers investing the time to learn GIS will benefit greatly. The program and data I used were free. Other programs cost quite a bit more.
Scaleability
Looking at the Cities map as an example, it is clear that many towns and resupply locations overlap when making a map of all the western states. Also, taking the John Muir Trail as an example, the extension off the PCT to Mount Whitney is just a few pixels and hardly visible on the Western States Maps, and the extension from Tuolumne Meadows to Yosemite Valley is visible, but hardly seen in any interesting detail. But this data is fully scaleable. For individual hikes I can zoom in on individual trails or states and make more detailed maps, with nearby towns distinct. Although my original time investment in this project was large, I plan to use it to easily make detailed maps of individual hikes.
Making Map Images
It would be nice to specify a range of Latitudes and Longitudes, and tell the program to make an image so many pixels high and wide. But QGIS has no such function. Instead, you have to scroll around, zoom in and out, and adjust windows to the size of the image you want. It's hokey, takes time, and gives poor results. Maybe another GIS program would be better for exporting the images you want as project results.
Making Image Maps
Some of the maps I placed on my website have HTML Image Maps so that you can drive your cursor around and find out the names of various features. The QGIS Plug In for making image maps works only for for points and closed polygons. So a line like a trail, highway, or river could not be automatically mapped. Where I mapped these by hand, it took a huge investment in my time. The maps generated by the plugin are huge; hundreds of kilobytes. This leads to long download times, and perhaps will hit my monthly bandwidth limits and cause month end shutdowns on my site. The automatically generated maps consist of polygons with sides one or two pixels long. For points, rather than use circles for mapping, many sided polygons are used. They are too big: many towns overlap each others, making finding town names difficult for users. I need to monitor availability of better automated image mapping modules and upgrade sometime.