After passing under a conveyor bridge and seeing heavy crane-type equipment both sides of river, the river splits, both left. The first split left is small, and at this point I started to hear a loud rushing sound. The next split left (mainstream) is a hard left so difficult to see until turned, but did slowly becaue sound is louder.Fast current could have taken me down to a log spannng the flow – looked to me like a keeper, possibly strainer. No way to navigate over or around. I clawed my way up muddy bank on left with nothing to hang onto. Found evidence that a hard shell had portaged recently, same spot. A less experienced paddler might have been caught in current, or slipped on muddy bank and pulled into the hazard. I suggest taking out the log.