There are bass in the river at least early in the year closer to Houghton Lake as far up as I could get a bass boat. I know that much from the past. They were spawning in the canals.
I don't think I've ever tried it in the fall yet. I made it quite ways up the river a couple times (in my crazier days I guess). I didn't jump any trees or blow out any beaver dams like the old veteran I went up the Cut River in a bass boat with but I made it around/over/under a few obstacles that wore me out. There were a few nice bass, and lots of keepers in some spots.
I like rivers in the fall though so some day I'll try it. Always appreciate information about new and interesting waters. I was always easily distracted in my bass tournament days by things like eagles, loons, alligators (not in Michigan of course... I don't think??), strange waves of possible alien origin and the occasional other species fish I just had to catch! Now I can do all that stuff with no guilt whatsoever! I like Pure Michigan! And other cool places too!