Just got back from a great run on Alto-Alto at about 560-580cfs. The metal re-bar on river right just after the wooden railroad bridge was only a couple inches out of the water and very difficult to see from the river left bank. If you plan to takeout past this bridge I would recommend running the mank (which is a lot different than I remember from several years ago) on river left or portaging.
Here is a pic of the railroad bridge drop from yesterday. The metal is actually a railroad rail. You can see it in the bottom part of the pic. Could'nt tell how far river left it goes. Water level in this pic is about 550 cfs.