Idaho Hot Springs Prep

Adventure Cycling announced a new mountain biking route, and this one is a doozy.  The climbs on the main route and the singletrack options are both tougher than the Great Divide Mountain Bike Route.

Washington Peak by Wsiegmund CC BY

The main route has 4 climbs of close to or over 3,000 feet in 10 miles, the highest point being at 8,719 ft altitude, when traveling in the direction AC suggests. Of the singletrack options, Secesh has one ascent of this caliber and Willow Creek and White Cloud each have one,  and in both those last cases you lose 500ft, which need to be regained.
In comparison, looking at the GDMBR, north of Breckenridge and including the Canada section, I could only find one section with that kind of gain/loss (Galton Pass) and if you take the route in the southerly direction AC recommends, it is a downhill.
My cycling partner looked at many blog posts of people who did it in its first year of available maps and came to the conclusion that you can probably only do 20 miles a day, at least on the singletrack, and not much more on the main route.
The main route is a 517.6 mile loop out from Idaho City and includes a singletrack option from Boise, allowing easy airline access.  There is a shortcut across the middle back east, in case you need to bail. The singletrack options, by their very nature, are long and remote.