I have fished Bone Valley twice. I once did it on a long day trip (I was in decent shape back then) and the other time my group camped out at the Bone Valley Campsite. I fished up to the cabin there both times. As I recall, that is where the stream forks into tributaries.
Fishing was good, but not spectacular. I caught some nice numbers of rainbows and browns from 6" up to around 10 1/2" with an occassional small speck thrown in for variety.
I don't think I would spend more than one day on the stream, unless you are just having spectacular fishing. I would also try hitting Hazel a mile or so above the Bone Valley confluence. On my last trip, we hiked and fished up Hazel past the Calhoun campsite. At Calhoun, there were a group of horsemen there that brought in electric generators and were indulging in ice cream! That cracked me up.