Saw this elsewhere and thought I'd pass it on...
[Knife River Construction has a $16 mil. contract to resurface Highway 49 from Downieville to the Yuba Pass. They are currently working between Downieville and Sierra City.
This project just started in May 2012 and will not be completed until NOV 2012!
You can get through, but it will add 1 hour plus to your adventure. You will be riding on dusty dirt and loose gravel in slow traffic w/ long wait times.
[if you have a final BELT drive machine (Harley) you may pick up a rock and bust your belt (like the guy I saw today).
It will be well worth it, the new asphalt is GORGEOUS!