Boulder

Hells Canyon of the Boulder is a high quality whitewater run set in a spectacular valley.  A bit of flat water leads to a massive rapid that is a portage for most or all paddlers.  A bit more chill water leads to the class IV/IV+ canyon section.  The rapids are often pretty long and continuous, and several have distinct moves to be made to boof or avoid big holes.  We paddled it at 1600 and the rapids were plenty juicy and distinct.  Flows in the 3500 range are rumored to yield Class V big water rapids that are long, continuous, and connected.  After 5-10 good rapids the whitewater eases off but remains fun to the takeout .