A thruhike is largely a head trip - so let's talk about head stuff. A few people can just pack up and go - but as part of the planning process, most of us do some research. Specifically, you might want to be reading and talking and listening.
I think anyone crazy enough to want to thruhike is probably smart enough to find a couple books and read them. No -- it's not a requirement. But it would give you a lot better idea of what you're getting into, of what the high and low points might be for you, of the rewards - and, sometimes, of the price that others have paid.
For the AT, I'll recommend a couple specific books because IMO they're the best introduction a prospective thruhiker can get to some of the realities of the Trail. Try Lynn Setzer's "A Season on the Appalachian Trail"; Larry Luxenburg's "Walking the Appalachian Trail"; David Brill's "As Far As the Eye Can See"; Cindy Ross's "A Woman's Journey"; and the 1975 set of Rodale books titled "Hiking the Appalachian Trail". All but the Rodale books are available from the ATC Ultimate Trail Store. The ATC phone number is 888-287-8673.
The Rodale books may be available at your local library (if you're very lucky).
Personal opinion is that among the plethora of AT books, these are the ones that'll give you the best introduction to what thruhiking is about - and what it really is. But don't let that stop you from reading anything else you can find - generally they're all good.
There have been several books written about the PCT, but the best that I've read is Cindy Ross's "Journey on the Crest".
We also recommend Karen Berger's book "On the Pacific Crest Trail". As I recall, these books are available from PCTA Their phone number is (916) 349-2109.
There's less variety with respect to the CDT, but I'd recommend Karen Berger's "Where The Waters Divide", as well as John Fayhee's "Along Colorado's Continental Divide Trail", and, yes - even Stephen Pern's "The Great Divide". You can get these books from Amazon.com.
For the PCT, both ATC and PCTA have Lynne Whelden's video - "How to Hike the Pacific Crest Trail", as well as several other more recent ones.
There are two videos about thruhiking the CDT. Joe and Carol McVeigh produced "Journey on the Continental Divide." This is a 1 1/2 hour video of their thruhike. Lynne Whelden produced "How to Hike the Continental Divide Trail" - a long (7-hour) video aimed at those intending to thruhike the CDT. Both of these are available from Jim Wolf at the Continental Divide Trail Society.
Lynne Whelden's lightweight video The Lightweight Revolution also applies to both the PCT and the CDT - with the caveat that it can snow any time of the year on either trail, so you need to be prepared. In 95, one of our friends had snow every week he was on the PCT - and in 97, Cindy Ross had sleet, snow and freezing rain on the CDT in Wyoming - in August. Don't ask about 2004 - you don't want to know. Well, maybe you do - check out the CDT journals at Trailjournals.com.
Another information source is the Internet. There's a whole gaggle of people who have their journals on publicly available Web pages. And there's a lot of information on the web pages for ALDHA, ALDHA-West, Trailplace, ATC, CDTS, CDTA, PCTA, Kathy Bilton, PATC and other maintaining clubs, individual hikers -- seems like everyone in the world has a Web page. How much of the information actually pertains to thruhiking? Some - but not as much as advertised outside of the actual journals, and even those should be taken with a large dose of salt.
Like the videos, the journals are very often "cleaned up" for public consumption. The emotional, sit-down-in-the-middle-of-the-Trail-and-bawl-like-a-sick-calf episodes are usually deleted. The "if-I-have-to-eat-another-Lipton's-dinner-I'll barf" is forgotten with the first hamburger in the next town. And the Oh-My-God-I-can't-stand-the-pain-anymore stuff rarely makes it into the public spotlight. Why? Because it's embarrassing, because it doesn't make us look like the Super-hiker, Got-it-all-together Thruhiker Studs that we'd like to be. It's an ego thing - it's a human thing. But those things DO happen - not to everybody, not every day, not even very often. But once again, it gives those who don't know about them a false impression of Trail reality.
Why do you think some people stop posting their journals the Web? Sometimes it's simply because they're too tired to write -- and sometimes it's because they stop caring about what the rest of the world thinks -- and sometimes it's because they're going through mental and/or emotional changes that they don't understand, can't control, don't know how to explain - and would be embarrassing if they were put in a public forum.
If I were gonna recommend a Web page journal for prospective thruhikers on any trail, it would be George "Exile" Steffanos's AT journal "Then the Hail Came" It's long (really long) - but then the AT a long trail, isn't it? But it's also real - he doesn't hold anything back. And IMO - it's just plain good reading.
Keep in mind that not all journals (in any medium) are good examples. Usually no one tells you that, but think about it - if you can acquire positive attitudes and knowledge by reading journals, you can also acquire negative attitudes, bad habits and a false impression of what's normal or even acceptable on the trail the same way.
In addition - a lot of us don't drag the camera out much when it's raining or snowing, so our pictures don't necessarily show "trail reality with respect to weather.
And then there are the email lists and forums. If you're a future thruhiker, I'd advise caution with respect to what you get from them. There's a lot of valuable information - but there's also some nonsense. I think one fault with the lists lies in the attitude that such things as cell phones, speed records, bear canisters or other political Trail "issues" have any real importance or relevance to those who are thruhiking. Those "issues" may be good "armchair discussions", but they're essentially irrelevant to the trail.
And the lists and forums generally have a "resident population" who use the forum as a personal communication medium. That can also be true of some lists. There's nothing wrong with that, but it can sometimes be hard for newcomers to break into the "conversation" and get real information.
The lists you want for thruhiking are those that discuss gear, techniques, trail conditions and (sometimes) the "soft" subjects like attitude, the mental/emotional side of thruhiking, etc. For example, one of the main topics last spring on pct-l was snow conditions while the discussion on at-l was about safety on the trail. Now if we could only get a discussion about snow conditions on the CDT.
Nearly all hiking/backpacking forums and lists place heavy emphasis on gear discussions. And the gear discussions tend to perpetuate the illusion that the "perfect gear" will ensure a "perfect hike". But aside from a few places like backpackinglight and pct-l, little serious importance or attention is given to lightweight gear or lightweight backpacking.
On the other hand, "lightweight" is an attitude - it's something you have to grow into. Don't be in a hurry about it, because for every increment of weight your pack loses, there's a corresponding loss of comfort, convenience and safety. But it's a good thing to know about even if you don't use much of it. A lot of people don't even understand what it is or the advantages it offers - so they never consider it to be of value for themselves.
Generally, the best posts on the email lists are those that get little or no response -- because there's no way to respond to them. The truth in them is self-evident and/or their main content is attitude. Attitudes are hard to respond to, but they're something that can be learned and absorbed by watching and listening to those who have them. Again - remember that not all of my attitudes - or anyone else's - will fit you. Like everything else, you have to pick and choose which attitudes you can live with and use - and sometimes you'll have to grow into them.
One of the most important things you can do is to talk. Talk to both past and present thruhikers - find out who and what they are - find out why they did the Trail - and how. Find out what they know about the Trail - where are the good hostels - which town stops are good - whether they'd do it again and what they'd do differently - what are the toughest parts of the Trail and the easiest - where did they resupply and how good was it - what are their best memories and their worst - there's a whole world of information just waiting for you to ask the questions. And thruhikers love to talk about the trail - any trail. If you give them an opening, they'll tell you more than you ever wanted to know about it. Yeah, I know about the Wingfoot and ALDHA books (and the PCTA town and mileage books) - but personal experience is better - and you'll find that their enthusiasm and excitement are contagious. You can't get that kind of enthusiasm and excitement from a book or even a videotape. And very often the information changes so fast that the books are out of date by the time they've been printed. Why do you think Wingfoot and ALDHA re-issue their books every year?
Go to the Gathering (either East or West - or both), go to Trail Days, go to Trailfest, go to a Ruck if you can possibly get there. The Gathering is best because you'll be talking to thruhikers who have finished the Trail, sometimes just days or even hours before. They'll have a much better idea about what the Trail really is than someone who's only been on the Trail a month or two and finished only the southern states. They'll know about ALL of the Trail rather than just part of it.
As a sidebar - the same general rule applies to "studies" or "surveys" that are taken after people have completed only a part of the Trail. For example, from personal experience, some of my equipment held up well as far as Damascus - and then it started to fall apart. And the difference in my attitude between Damascus and Monson was utterly shocking to a number of people who had known me for years. A gear (or attitude) survey taken in Damascus would have gotten vastly different answers from the same survey taken in Monson. Which would have been more accurate?