Jake, it is the first Engineered log jam below Allen's Bar. I am pretty sure there are three, two of which are right at the road bank just a bit farther down river. The first you come to is just above these, on river left in the main channel/bed, and there is a huge sweeper that sticks out over the majority of the flow.

The river shallows up just as it gains speed and dives into the hole. Tough not to miss an oar stroke as you approach, but as Leland said, as long as you are on it an set up far right and dig when you hit the hole, it goes.