I guide down there. A few days ago one of the rain storms created some significant sediment deposition at the mouth of the side canyon below Sledgehammer and Hey Diddle Diddle. Right below that, near the entrance to the narrows, there was a pretty significant movement of the rocks, rings and dirt from the pipeline right down to river level. I expect that pile of debris to slip into the river pretty soon, especially if the water bumps up from rain, or another big storm comes through.
To me, these new rings in the river aren't that concerning, only because I've always been sketched out about the rings, and the rings that we can see now are vastly outnumbered by the ones we can't see that have fallen in in the past. As always be careful down there- lots of steel!