Sounds like you can ride the IAT, according to MaineErik.  But man, if the IAT is anything like the AT through Maine, how much actual riding you'll be able to do might be limited, at least over the higher terrain.  I swear the folks that built the AT through Maine (Myron Avery was the man!) had never heard of switchbacks, or couldn't be bothered.  Straight up, straight down.
I assume you can't ride in Baxter besides the tote road.  I'll have to check out those links Erik posted earlier. 
I did the AT across Maine in June (continuing on to Georgia), and holy shit, the bugs can seriously drive you crazy.  Even if you get away from their biting at night, the buzzing.... zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz 

Shame you have to bypass the Pasayten Wilderness.  I've hiked in there a bit, and it's unbelievably gorgeous. Plus I've got some family history up there, so it's a special place to me.  My dad was on trail crews up there as a young man, and I've heard stories my whole life about those days... blowing up stumps with dynamite, packing in supplies with horses or having them air-dropped, fighting fires... all sorts of manly shit.

Mike, I've got a Maine Gazetteer you can borrow.  I can definitely attest to the bugs in the Maine woods in early summer.  It's pretty amazing.
I didn't realize you could ride on the IAT, or I'd have suggested that earlier.  Definitely cannot ride on the regular Appalachian Trail! (the IAT extends from where the AT ends at Katahdin up to Cape Gaspe in Quebec)
Sounds like a cool trip. 

Sounds fun. Plenty of interesting, little-traveled terrain in Maine.  I know from traveling the Maine woods on foot, watch out for the log trucks on their haul roads, those boys move!  Monson, the last town on the AT (or first if you're going south) seems like it would be a good starting point.  I was planning on riding the perimeter road at Baxter this summer, but never got around to it.  Certainly scenic, dirt road, open to bikes, and free of log trucks.  Plus, plenty of places to fish and camp.

I've got a complete set that haven't left the house yet.  I've had them a couple years, but they're essentially brand new.  It's not looking like I'll get to take that trip any time soon, so I can let them go...

Email me if you're interested: willapa.waterstrat@gmail.com

Will

It's a shame you can't ride in the wilderness areas.  The Pasayten Wilderness is one of the most beautiful places I've ever been to, but only on foot.  Why they'll allow a 1000-lb horse with metal shoes is beyond me.  Guess it harkens back to the cowboys, but that's a whole 'nother can of worms.  My old man worked on trail crews when he was in college, and was responsible for putting a lot of the route through the Pasayten.  It would be worth walking across it with a bike on your back.  I imagine the rest of the high alpine meadows in Washington are just as gorgeous.  I miss my home state... though Vermont ain't bad.

Does that mean the xvtmtbr project finally got finished?
I'm up in Stowe.  Count me in!
WILL
 

I like where this is going!   
An Eastern Divide route...  When I hiked the AT (yeah, all of it) many years ago at the height of my racer-geek days, I kept thinking how awesome it would be to be able to ride a similar route.  I often pretended (mostly on downhills) that I was riding a bike, complete with rad x-ups and wooshing noises.
Keep up the good work! 

I'm a big fan of the Pentax Optio W-series.  I'm on my 3rd one.  I had the first one (Optio WPi) for 3 years until I dropped it in a waterfall and couldn't find it until 3 weeks later.  It actually turned on at first, but proved to be a goner.  The second one (W60) was stolen from a shitty hotel room in Tennessee.  I just got my 3rd one (WS80), and it's the best one so far.  They're cheaper than the Olympus ones, and there's no external moving parts to get jammed with crud.  The only complaint I have with it is that the location of the tripod mount made it hard to open the battery hatch without modifying the mount a little.  
Here's the one I've currently got:  
http://www.amazon.com/Pentax-WS80-Waterproof-Black-Orange/dp/B002KE48CK/ref=sr_1_14?ie=UTF8&s=electronics&qid=1267586647&sr=8-14
It also happens to be extremely light.

Edit:  I forgot to mention that it's waterproof and shockproof.  Also, in my limited experience, cameras that run on AA's eat through batteries.  The charger for this camera weighs less than a couple AA's, but you've got to find a place to plug it in...
It doesn't have a viewfinder (peepsight), but I've gotten pretty good at aiming it without being able to see the view on the screen on sunny days.

Are you looking for road or offroad routes?

Yeah, there's only a few sections where horses are allowed (the Smokies is the only one I can remember, and that was 10 years ago).  It's like walking in a knee deep ditch filled with horse shit.  Wait, it's not like that, that's what it is.  I really never understood why horses are allowed in wilderness areas and bikes aren't.  A thousand pound animal is clearly does more damage than a 30 pound bike...

no way on the AT, and most of it would be unrideable...

Absolutely true.  Having hiked the whole thing, very little of it is rideable, especially in the parts that are most interesting (New England).  The AT has been around so long and has such a culture around it, it'll never allow bikes.  I really wish they'd get rid of the horses in some sections (e.g. the Smokies).

Same here.  I bought a 9spd Dura Ace STI shifter for my 'cross bike on closeout several years ago.  Wanted 9spd so I'd be able to run mountain cassettes if I decide to go touring on it.  Guess that doesn't matter now...

Aw man, why 10? 9 was already more than enough.  I hope they'll keep making 9spd for a long time, because I sure don't want 10spd...
 

DeLorme gazetteers are great for finding dirt roads and roads you might not have known were there.  They're not very portable, but you can photocopy the page or two for your specific area and carry them along with you.  I do just that when exploring dirt roads here in Vermont.  A heck of a lot cheaper than a GPS!
You can also use google earth/maps to do some aerial scouting before you head out too.  Dirt roads show up very well in satellite imagery...

Were you near a millitary facility?  I've worked on some millitary research facilities for my job (I'm a geologist), and I've seen cell phone signals be completely tweaked out on the site, and 5 bars offsite.  I know they're different satellites, but maybe some facilities have some way to block or distort signals.

I would add that the best single piece is a lightweight balaclava like the Craft one.

Really?  I've lived and played outdoors in cold climates (Maine/Vermont) for lots of years now, and I've never had one of those.  Maybe I ought to try one.

My brothers and a friend took a "spring break" (i.e. February/early March) trip to Pisgah way back when we were in highschool (mid 90's).  Rest assured, it can get plenty cold in the mountains of NC in winter.  There wasn't a whole lot of snow, but it was cold enough to freeze water in bottles.  I distinctly remember my camelback valve was a bit leaky, and dribbled on the vest I was wearing, eventually leading to a big icy patch.
It definitely won't get as cold and snowy as New England (I'm also now a Vermonter), but it can get pretty cold.  The same layering rules pretty much apply to all winter activities, so much of your winter cycling gear will work just fine for XC skiing, snowshoeing, hiking, whatever... if you ever move to a colder climate.

Off topic, but how does one get a job as a field geologist in BC?!  Oh man, that'd be amazing!  I'm a "field geologist" in Vermont, but most of my "field work" involves collecting groundwater samples from industrial sites around New England...

I've been using WTB SST's (the original ones) since the late 90's.  I've tried some others in the meantime (Selle Italia Flite, Koobi, Bontrager, F'zi:k Nisene, Specialized BG, etc), but I keep coming back to the SST.  I can MTB all day on them, but my ass hurts after an hour on the road.  Maybe I should try something different eh?  Perhaps it's time to try a Brooks...
Anyone want to trade a Brooks B17 for a nearly new Flite?