Bruneau - Jarbidge
I've paddle some of the the tribs in the Bruneau. First -- don;t bother with the East Fork (Clover Creek) it's full of willows and a miserable experience. (The same is true for Mary's Creek entrance to Sheep Creek).
Pervious years, I;ve done the Jardige to the Bruneau in 3 days. It's a beautiful, unstressful trip. Last year, we did Sheep Creek which absoultely blew my mind. Imagine paddling through the Zion Narrows, except the walls a ryolite extending 800-ft above you and riddled with caves and arches.
The shuttle into sheep is the easiest, followed by the West Fork. The horror story that people recount is actually to the put-in on the Bruneau. Self supporters should do one of the three tribs (Sheep, West Fork, or Jarbide) for a start. You can probably hire a reasonable shuttle in Bruneau for these. Last we checked, the recommended driver charged upwards of $200.
There's a gage on the West Fork in Nevada. Late March is probably on the early side, but may work. Last year, we were in there in May with a similar snowpack to this season (The jardige Raqnge in northern NV is aorund 12,000 ft). Sheep contains about 3 class IV+/ V- drops that are easily portaged at the flows we had (1800-2000 on the Brunea gage near Bruneau, ID -- note the NOAA nwrfc forecasts this point with pretty good accuracy.) It is intersperesed with a few class II-III drops. There was very little wood in the river. Once you hit the bruneau, the rapids are big water feeling class III+ (to IV+ if you fall in a hole) with class V+ poinson ivy along the banks.
The jarbidge is straightforward and well documented on the internet and in guide books.
A friend soloed the West Fork with a portage at Julie Wilson Falls. He speaks highly of it.
Feel free to PM with specific questions. It's a beautiful, remote region in which travels are always reminded of the fragility of man. Definately a great trip to undertake.