Best to call USFS for current conditions on this segment which is called the Magruder Corridor. It is full on 4x4 vehicle conditions for a good part of the way.

We tried to bikepack it 2 summers ago but had a catastrophic hub failure 3 miles in, so decided to drive it instead to do a recon for the future and do misc day hikes along the way. The route from Red River to Darby is a mix of conditions. Roads are well maintained gravel on the east and west sides, including a stretch of ~10 miles of pavement on the east side. Conditions are a bit rougher are narrow 1 lane road with turnouts in the middle segment, but 4WD wasn't needed. The spur to Burnt Knob is highly recommended but pretty gnarly 4x4 road, so was happy to park the Tacoma and hoof it up on foot. Overall very good conditions for bike packing, but water sources are limited to nonexistent between Bargamin Cr. and the Selway without a hike so make sure that you can carry plenty. There are a few more details here on www.bikepackingroots.org/wild-west-route.html.

curious of the road conditions on this route. Are these roads somewhat maintained, or are they full on 4x4 roads. I am looking into bike-packing around the Salmon River Drainage this fall. Thanks for any pertinent info.