So I'm participating in this "race" next month, and considering a bike-heavy route along the eastern edge of Rocky Mountain front.

Any info on the bikeability of the following trails would be greatly appreciated. (I've checked and according to the FS they're all legal, I'd just like to know which ones might be mostly unrideable.)

South to North:

CDT from Roger's Pass to Blowout Mountain
East Fork of Falls Creek (Tr. 219 and 299)
Blacktail Gulch
Rierdon Gulch
Clary Coulee (Tr. 177, 153)
North Fork of Birch Creek (Tr. 121, 104)
South Fork of Two Medicine River

I know I'm most likely whistling in the dark on this one, but thought I might get lucky with some Helena or Great Falls folks.