Parked at the mouth of Hell Roaring Canyon. Had been looking forward to visiting the Denis Julien pectroglyph found at this canyon for some time. We stumbled/bumbled around and couldn't find it. I thought it was along the river when actually it was in the canyon proper. Hard to believe I never did see the site since it is obviously well marked and located just off this major interchange. None of which are visible from riverside. We were yards from the road and sign but turned back before that. Bonner and Rich did eventually make it.