On a side note...borrowed a friend's eTrex 30 and I am NOT impressed by the speed.

Do you mean the speed by which your current position is adjusted on the local map? I didn't notice any hickups at 20-30 km/h at a map scale unit of 500m. If so, I can't imagine that it is relevant for the Transcontinental Race.

Ashley Benns is about to finish. He is labeled as a veteran, but I think this is his first TD race. In 2012 I toured a big part of the the Divide route with Ashley, from Wise River to AW. He is great company.

Ashley is a professional yacht captain for private yachts. This is a world of luxury and leisure, making it even more remarkable that he volunteered for the hardships of the TD race. As preparation for the TD he rode on his bike from Key West in Florida to Banff, mostly on the GD route. Must be like 2 months on the bike. Congratulations Ashley!

I struggled withe the limitations of the Vista HCx too. I am so glad that I bought an Etrex 30. No size problems, much better visibility in daylight, more user-friendly operation. I guess also longer battery life.

I would also ask at Escalante Outfitters if you haven't already, they are pretty friendly and could be helpful.

Thanks for that very helpful piece of advice! Outfitters brought me in contact with a local biker who had all the tools and even a spare new derailler. I can move on.

A holy grail for a bikepacker in Wa state is doing the historic wagon route of the Naches Trail between 410/Rainier and Yakima.

I have been looking for a route from Yakima up along the Little Naches River and down in the watershed of the Green River. I found a set of forest roads that crests at about 5000 ft. However my Benchmark Atlas of WA-state has the upper Green River basin as 'closed to the public'. Does this mean that all forest roads in that area are banned for bikers?

In Escalante there is nothing. Is there a bike shop in Flagstaff that I could contact?

I am stuck with a broken rear derailller in Escalante - UT. It's a Shimano Deore XT - M772, 9 speed. Does anyone out there have a suggestion where I can order a new one, or a compatible type, and have it sent here asap? I am from Europe and not familiar how this works in the US. Any help appreciated!

I don't know which country you are from, but you can order them in The Netherlands
http://www.bikester.nl/revelate-designs.html?

The Topic Poster already found his way in and out SoCal. See http://forums.mtbr.com/california-socal/bikepacking-socal-west-east-899983.html

I don't know if snow melt rate is linear?  It has been warm and dry in Salt Lake.  So by May 20, you might be good up to 8400'?

Thanks for the info. I hope it's non-linear, as around May 20 I want to crest the 9300 ft dirt pass between Bryce and Escalante, suggested by joeuser.

I guess you can do the 500 miles section from Antelope Wells to Cuba-NM, including the scenic dirt road over the San Mateo Mtns and Mesa San Luis. The route touches 8000 ft a few times, similar to the AZT Race which is currently run. North of Cuba the GD crests the Polvadera Mesa, 10,000 ft, which is probably under snow.

How accessible are the starting and/or end points for the single track options.  Would it be crazy to do the main loop first and then drive back and do the optional sections?  Is that even possible with low clearance vehicle?

If you look at the single tracks as parts of a small loop, then each of them has at least one point on a paved state road: Secesh on SR-21 near Payette Lake, Eagle's Nest on SR-22 near Cascade, Willow Creek on SR-61 at Featherville and White Cloud on SR-75 at Stanley.

If you look to the points where they connect to main route, the Idaho Atlas from Benchmark Maps makes a distinction between 'unpaved roads' and 'high clearance or 4WD roads'.
Presumably unpaved means roads suitable for low clearance car.
- Secesh : both points on unpaved 412 ;
- Eagle's Nest : start on unpaved 400 ; end on 417B which looks like a 4WD (uncertain ; 3.8 mi towards Cascade is unpaved 417 which becomes paved after 3.1 mi).
- Willow Creek : start on unpaved 268 ; end on unpaved 227, quite near to paved SR-61 at Featherville ;
- White Cloud : start on unpaved 194, close to paved SR-75 ; end on paved SR-75
I guess a brief scrutiny with Google Maps in satellite view will tell you a lot more.

Is 60 miles reasonable for a daily average. (I did a short loaded hilly road tour last year and did 70 80 mile days)
As there any place we can find the elevation gain of each segment? (for instance the Ketchum-Stanley section)
 

On the Great Divide MBR with a fairly loaded bike (not the light bikepacking set-up), I did 63 mi / 4100 ft ascents on average per day , so 60 mi/day sounds reasonable to me.
Note that these ascents were measured by a Sigma bike computer with altitude meter. This is a barometric device that generally gives a lower ascent figure than a GPS device (about 15% less).

I mapped two stages of the Idaho Hot Springs route with Ride-with-GPS, one of them the Ketchum-Stanley section. I assume that you can view the elevation profile here (maybe you have to register first): http://ridewithgps.com/routes/4335889 .
It amounts to 66.3 mi / 4562 ft ascent and I expect to do it on a single day.

It took me about 30 minutes to map one stage with the ACA map cues at hand. I suggest that you map some stages yourself! I found it very educating for learning the terrain, especially in satellite view, and fun to do.

If you zoom-in on satellite view, it is usually possible to see whether a road is dirt or paved (viz. black surface; often you can see the white line). The level of detail is not enough to rate the quality of the dirt surface. But hey, this is supposed to be an adventure route!

I hope so. I personally traveled every inch of the main route, and the narrative directions were created from what I saw - and what you will see - on the ground. There are numerous instances where every other map said something to be true, when in fact, it is not true. For instance, you will find virtually no map which has the main route dirt road on the northeast side of Galena Summit, but it's there. Although, a bit hard to find at first.

Casey, I had no problem to find the dirt road northeast of Galina Summit on Google Maps (satellite view), but I was puzzled by the cue at 27.5 mi from Ketchum "Just before turnout..." . I guess the creek to cross on logs is on the LEFT of SR-75? The cue doesn't say this clearly. I hope each piece of the puzzle snaps into place at the spot. Still I wonder why you didn't opt for the Titus Lake Trail to crest Galina?

Maybe you could phone one at the bottom of this list what they charge for a shuttle from El Paso to AW.
I am not sure where Juan More Time shuttle is located, but he did bring riders to El Paso.
http://www.adventurecycling.org/default/assets/File/Routes_Maps/pdf/GD_shuttle.pdf

Mathieu, are thinking about tying in to the new ACA Idaho off-road route from Utah?

Mike, I outlined my route on Crazy Guy.
http://www.crazyguyonabike.com/doc/?o=1&doc_id=13840&v=3A

I might have a try on Thunder Mountain if I can drop my load at the CG, but I am not as nimble as Alpenzorro!

Joeuser, thanks for your suggestions and GPS files. Since my first objective from the AZ/UT border is Bryce NP, I will probably follow the Cottonwood Canyon Rd to Cannonville. Should be scenic too.

From Alpenzorro's route I liked the idea to go from Bryce over Escalante Canyon Rd/Main Canyon to Escalante. I hope that the pass (9300 ft) is snow-free by end of May. It was apparently in May-2010.
Amazing route by Alpenzorro!

For a newby I would definitely recommend a mountain bike with front suspension, so no Salsa Fargo 2!
The shox can be fairly basic and inexpensive. It will still absorb a lot of the impacts.

You best spend your first 20 dollars by buying the latest edition (2013) of Michael McCoy's book Cycling the Great Divide.
http://www.amazon.com/Cycling-Great-Divide-Americas-Long-Distance-ebook/dp/B00FN65UII/ref=sr_1_1?ie=UTF8&qid=1394317396&sr=8-1&keywords=mccoy+divide
It has sound and proven recommendations on the bike type and on other gear issues.

Colen, I'll probably follow your tracks through the Cottonwood Canyon and Burr Trail , then going north along Capitol Reef NP (UT).

ChrisX, thanks for balancing the views on biking through reservations. My own impression, after cycling half-a-day through the Navajo reservation near Leupp-AZ, was also that through-bikers are a bit of a surprise to the locals but not treated with hostility. Anyway, I don't expect shoulders on dirt roads.

Addy, thanks a lot! I had read about the Kettle Valley Rail Trail in the Adventure Cyclist (2009), but didn't know that the trail extends much further than from Midway to Penticton. I now have Cycling the Kettle Valley Railway by Dan Langford on my e-reader and consider it a serious option.

While Idaho is like a box of chocolates for a dirt road aficionado, my survey of Washington's road atlas was a big disappointment. For some time I was dismayed to believe that I had to cross the Cascades Range on pavement! Recently I found a short piece of dirt that should carry me over the Pacific crest:  from Yakima on WA-40, continuing along the Little Naches River and descending along the Greenwater River towards Enumclaw. From there north to Abbotsford. Not a very appealing route, but my best option so far.

Another option is to go north of the Colville reservation via Kettle River - Toroda Creek - Chesaw - Oroville into BC. The US part seems fine to me, but I haven't yet found a similar continuation on the BC side.

Any suggestions are highly welcome.