Home - Photos - Travel - Movies - More

CDT-ROM Information
Annotated maps of the Continental Divide Trail. Updated annually.

When I was preparing for my hike of the CDT in 2001, I got frustrated by the lack of good, detailed, inexpensive, CDT-specific maps. So, I created my own and have put them all on a CD-ROM that anyone can use to print their own copies.

General Information
The maps are digital images, intended to be viewed on a computer screen, or printed on 8.5x11 sheets of paper. All it takes to create a complete hard-copy set is:

  • Access to a computer
  • A standard color ink-jet or color laser printer
  • ~140-280 sheets of good hi-res paper (depends if you print double-sided, and if you print all the maps)
  • A couple ink cartridges (if you use an ink-jet)

The maps are based on the USGS 7.5 minute (1:24,000 scale) topographic quads (spliced together, so the seams of the USGS maps aren't an issue). The individual maps are set-up to be printed at 7in x 10in on an 8.5in x 11in sheet of paper, which puts the prints at a scale of about 1:60,000, or 1mile per inch. All of the information from the 1:24,000 original maps is there, it's just shrunk into small fonts and tiny lines. Some people have printed the maps on 11in x 17in sheets of paper. This will make some of the fine detail a bit easier to read. Though, I rather like the 8.5in x 11in size - folded in fourths, they fit perfectly in a pocket (and they're a bit lighter for all you lightweight folks).

I've drawn the trail with a red line & a bunch of alternate routes in purple. I've added a bunch of notes to the maps based on feedback I've received from dozens of hikers through the years. I hope the maps will get better and better with each passing year. If you have any comments or notes you think should be added to the maps, let me know. It's easy for me to edit the master copies.

Getting your own copy
Just e-mail me: jonathan@phlumf.com (include your mailing address) & I'll send you a CD-ROM.

The maps are free of charge, but I do appreciate anything you can send back to me to cover my expenses & encourage me to continue to do this. The material costs of the CDs, printing & mailing is only a few dollars, but I have spent literally hundreds of hours working on these maps, doing updates, burning CDs, printing labels, etc. This hasn't been the most profitable activity in my life, but I have had some fun doing it! My return address will be on the package you receive. Or, you can use paypal.com to send something to: jonathan@phlumf.com

If you want to download a sample copy, click here. This is a map in southern Montana, the file size is 2.05MB.

About the Updates
I generally update the entire set of maps over the winter, and try to be done by the end of February. If you want the current year’s maps, just ask for it. If you want me to put you on the list for the upcoming year’s update, let me know. I usually have a long list… and will let you know if there is any change in the release schedule planned.

I do not keep a log of exactly what’s changed on each map each year. Sorry about this, it’d just be too much work to deal with. I update the maps in a bit of a haphazard fashion based on numerous (sometimes conflicting) inputs, so it’s just too much to track.
However, I do have a list of which maps have changed from the previous year. The change might have been a complete overhaul, or just fixing a typo... Usually it's somewhere inbetween. Anyway, you can see the list here.

If you have a set of maps from 1 year previous, you’ll probably be OK to use those. Even a couple years back, and you’ll probably be OK, but you might miss-out on some new routes and such

About the 2014 update
The 2014 update contains a lot of feedback from a variety of sources. Most of these changes are minor, but there are a few areas that have seen some big improvements, for example:

  • All the maps from the border of Canada to Rogers Pass (first 20 maps) have been re-done.
  • There's a new alternate route that goes right by Mt. Zirkel
  • There is a new route in the South Sawatch / Collegiate Peaks area of Colorado
  • The Chain of Craters route in New Mexico now has detailed maps
  • The dead-end route just south of Pie Town is included
  • The old overview maps have been removed from the CD in favor of an online interface that you can see here.
  • There are now a total of 274 maps: 79 for Montana, 56 for Wyoming, 52 for Colorado and 76 for New Mexico.
  • If you have a copy of the 2013 maps, you'll probably be OK for 2014, (you shouldn't get lost or anything). Though, the 2013 versions should be helpful throughout the trail, and you might get jealous of other hikers who have newer maps. You might want to get the 2014 CD and just look at the electronic files to see what's new, and maybe print a few of the updates.

The Map Images

  • The map images are all stored in .gif format, they have 256 colors (also referred to as 8-bit color).
  • I chose the .gif format because it is a relatively compact file format, and does not introduce any compression artifacts (like .jpg) which can make detail difficult to read. Plus, image files with this much detail don't compress well in .jpg format anyway. .gif is very limited in the range of colors it can display (so, it is not a good choice for things like photos), but that doesn't matter so much for these maps.
  • Most of the maps are 2250 x 3000 pixels (dots). There are a few exceptions (maybe 3 or 4 maps are other sizes, but all smaller than 2250 x 3000). Note that at 300dpi, that comes out to 7.5in x 10in.
  • Nearly all of the maps are based on the USGS 1:24,000 or 7.5 minute map data. A few maps in New Mexico are based on 1:100,000 USGS data. Those maps are labeled as such, and it should be obvious when you look at them.
  • When printed, the maps have a scale of about 1mile/inch, or roughly 1:60,000 (all the 1:24,000 data will still be there, it'll just be shrunk into fine print)
  • The maps are numbered north to south generally. Some of the maps have "letters" as well: (i.e. WY28a). These are instances where alternate routes required extra maps, or they provide coverage of small "missing areas" between some maps, or they are "zoomed-in" detail sections of some of the 1:100,000-base maps. It should be easy to figure out what's what when you're out on the trail.
  • The Columbus Route maps are not on the CD. They're available for download on-line. The navigation interface should work smoothly, provided you're on-line as well. To download a .zip of all the Columbus maps, click here.

The Route

  • The route I've traced on these maps is a continuous "CDT route". I've also included a number of alternate routes. In many places, there's some debate about which the "best" route is, particularly in southern New Mexico. Nobody can tell you which to do - just hike your own hike!
  • The red lines show what I can best describe as "the main route". Usually it's the designated CDT route, and usually it's the route I prefer. In a few cases, it's neither of those things. Away, it's a continuous route. If you find a map with two red lines… just hike either one (do not hike in a circle... unless you want to hike in a circle).
  • The purple lines show alternate routes. Usually, I've included notes in the margins to describe or criticize the alternate routes.
  • There are a some maps with grey lines. These are roads or trails that were not clearly visible on the USGS maps, but I wanted to show them as reference points. I have only done this in very selected instances. There are plenty of roads & trails crossing the CDT not marked on the maps. These are often described in the notes.
  • Any dashed line indicates that there is no tread on the ground in that section (so, it's cross-country). Keep in mind that many parts of the CDT have occasional cairns or signposts or very faint tread or nothing at all… I apologize if they're not consistently marked on the maps. If you hike the trail, hopefully you'll understand why it's very difficult to decide if a particular route is technically cross-country or not.
  • The mileages on the maps show the estimated distance between any two "stars". I added the mileages to make it easier to plan your day. I measured the mileages by "rolling" the distances on a printed set of maps with an electronic distance measuring tool (and in some places, just eye-balling it). It's kind of difficult to get an accurate measure when there are lots of twists and turns in the trail... especially at a scale of ~1:60,000! So, the mileages might be a little "off"... usually short if anything (but consistently short I hope). I can almost guarantee that my mileages won't exactly match-up with mileages in the guidebooks or other maps. But in the end, they should help you out. There are some places without mileages marked - it's just a lot of work to keep all these updated... You get to have fun "eyeballing it" in those places!
  • The Columbus Route maps are not on the CD. They're available for download on-line. The navigation interface should work smoothly, provided you're on-line as well. To download a .zip of all the Columbus maps, click here.

The Notes

  • The numbered notes should be self-explanatory. The numbers are generally "very near" to whatever I'm referring.
  • In most places, I've indicated for which hiking direction the notes are intended. If a note doesn't specify, assume it's intended to make sense primarily for southbound hikers (because I hiked the trail N->S, and some of the notes are from my original hike)... or more often, either direction.
  • Since 2001, the maps have been pretty extensively overhauled. Special thanks to everyone who has given me feedback - there are too many of you to list. The CDT-ROM works because of YOU!
  • I've made some notes regarding road numbers and private property in many places, but not "everywhere".
  • The map labels in the upper left hand corner of each map are there to help you keep the maps organized in case you print a set. All the labels are in the NW corner of the map. All writing on the maps is such that geographic north is "straight up".
  • The missing areas, or "white spaces" on the edges of many maps are there to save ink in the event that you want to print a set. I've tried not to erase anything that is vital.

The Overview Maps

  • New for 2014 - Visit my website here to see the map overlays drawn right on Google Maps. As of the CD publication, this only includes the first maps in northern Montana, but I'll be adding the rest soon... just check back. 
  • There seems to be a glitch in the way that Google Maps prints these. But, I'll be adding some printable files to the same link as above when I get all the overview maps added.
  • I've removed the old overview maps from the CD. They weren't very easy to read, few people printed them, and they were a mess to update.

Using GPS and the Compass Rose

  • Click here for more information about using GPS with the maps.
  • You don't need a GPS to navigate the CDT, and I was a little reluctant to add GPS data. But, people were asking about it, and thanks to a suggestion I received for a clever method of incorporating GPS data, I went ahead and did it. This was added in 2004.

Viewing the Maps

  • I have included a "navigation" web page on the CD that's written in html. It's accessible via the link on the "CDT Maps" page & should be self-explanatory. This should work on Apple systems as well.
  • If you don't have any graphic viewing or printing program, I'd suggest downloading the free viewer - Irfanview, available at: www.irfanview.com
  • Or, you can use any other software that displays the .gif format, such as the built in viewers in some operating systems, Photoshop, Photopaint, Paint Shop Pro, GIMP, or some similar software.

Understanding Resolution... for the Technical Novice.

  • All digital images (including these maps) are made from a mosaic of colored points called "pixels" or "dots". Look really closely at your computer screen, and you'll see the pixels.
  • The size of an individual pixel is arbitrary - if you look at the same image on different computers it will sometimes appear to be a different physical size. This is because different monitors and video cards have different capabilities to create small/fine pixels.
  • When you display an image on a screen, each pixel of the image will take up one pixel on your screen. The map images are comprised of (portrait) 2250 columns of pixels by 3000 rows of pixels, or 2250 x 3000. If, for example, your computer screen displays 1024 pixels columns x 768 pixels rows (1024 x 768), you'll only see a portion of a map & you'll have to scroll to view the whole thing.
  • Many software "viewing" programs include a feature that allows you to look at only a certain percentage of an image's total pixels (some web browsers do this automatically). This has the affect of shrinking the displayed image so you can see the entire image on your screen. When a software program does this, you'll lose some of the fine detail in the original image. There are advantages to viewing a map either way.
  • When you want to print an image, you often have to tell your printer how big to make the printed pixels (or "dots"). This is done is by specifying how many pixels are contained in a linear inch (as if the pixels were stacked end-to-end). This measure is called "dpi" or "dots per inch" (where a pixel = a dot)
  • When you open a .gif file, some software will assume the file should be printed at 72dpi. The software may make this assumption because most computer monitors display graphics on the screen at approx 72dpi. (There are about 72pixels per every linear inch on most older monitors). The .gif file format is most often used to display computer graphic images that are never printed.
  • The maps are intended to be printed at 300dpi, so that they will come out to 7.5 inches x 10 inches. Depending on the software you use to print, you may have to "tell" your computer the image is a "300dpi image". How to do this will depend on the software you use. Some printing software will allow you to "fit the image to a page" or "reduce" the image. If you're not getting the results you want (if the image prints too large or the edges of the image are cropped), play around with the settings used in your software.

Printing the maps

  • Color laser printers have gotten a lot better in the past couple years, and in my opinion are now the best choice for printing the maps. While you can get slightly finer detail with an inkjet & good paper, the color laser printers have a number of advantages. These printers might cost more up-front, but the color toner lasts for thousands of prints (saving you money in the long run). Color laser prints are also much more durable wrt/ wetness, and you can probably get-away with slightly cheaper paper. The laser printer ink might flake-off at folds in the paper, but the maps should hold up well enough for the amount of time you need them. If you're going through 2/day, they don't need to last long.
  • Most people use ink-jet printers to print the maps. I recommend using good ink-jet paper. There are a variety of brands, but the point is - don't skimp. The advantage of using good paper is that the fine detailed writing in the maps will be clear. With normal paper, the ink will "bleed" just a little, which blurs details… no matter how good your printer is. There is a LOT of fine detail on these maps. You can find high resolution paper at any office supply or computer store.
  • High resolution paper also holds up reasonably well when it gets wet. Inkjet ink will bleed profusely on regular paper with the slightest moisture. This is a very important consideration out on the trail.
  • Waterproof paper is now available, but it is expensive. On a typical hike you'll go through about 2 maps a day. I wouldn't bother with the waterproof paper unless you intend to keep the maps for a long time, use them again, or pass them along to future hikers.
  • The where's and how's of printing will depend on your printer and printer set-up & the software you use to print. In order to see the detail on the images, you will need a printer that prints at least 300dpi. Nearly every ink-jet printer sold in the last 6 years will print at this resolution. Color laser printers sold in the last 2-3 years should be ok too. If you have an old or extremely low-end ink-jet that cannot print at 300dpi, the printouts will not be clear.
  • Batch printing: This is something you'll want to do. You can set up your system to print the maps in batches of "many at a time", so you don't have to baby-sit the process.
  • If you have Windows 7, the easiest way to print the maps is to navigate to the appropriate map directory using Windows Explorer, select the files you want to print, then click "print" at the top of the window. Select the "Fit picture to frame" option, and "Full Page Photo" option. (I'm told that Mac OS9 & OS10 have similar options, and Windows 8 probably works the same way)
  • Tip: You might only want to print about a dozen maps in a batch (or fewer). If you print too many, it can be too much data for your printer to handle, and you'll get weird errors & system crashes.
  • Tip: If you have double-sided high-resolution paper, you may want to just print odd-numbered maps first, then run the paper through again & print the even maps, etc...
  • Important: If you use other printing software and it has a "fit to page" option, you may want to use that. If it doesn't, try to reduce the image to 25% to get it to fit on a normal piece of paper. If you don't do this, the printing software may crop the edges of the map, and just print one small section, frustrating you beyond belief.
  • Print time will depend on your printer and computer. With a fast setup, a map may print at less than 10 seconds per page… or faster. On a slow one…???
  • I went through about 2-2.5 ink-jet cartridges to print a whole set of maps in 2001. Your mileage may vary… There are sources on the internet for cheap ink jet cartridges… look for them! I got mine for $5 each. The color in cheap ink will usually fade more rapidly than other ink, but that's not really important with these maps.
  • I don't recommend using black-and-white laser printers. There is a lot of information on the maps that can only be seen in color.
  • Some people have taken the maps to their local copy-shop to have them printed. This can work fine, but is usually quite costly. The results you'll get won't be any better than home-printing. If you're just not comfortable with computers and printing, etc... Printing the maps is a great way to learn!... or ask a friend, neighbor or family member. Surely someone you know would be willing to help!

Home - Photos - Travel - Movies - More