I was down by the Mississippi river near St. Louis, MO. And a fisherman told me that there was good bass fishing in the main channel.

The water is very turbid and flows fast. It was the main channel of the Mississippi river. I always catch drum, carp, and catfish.

The water is fast and its generally not safe for swimming.

I know that bass and other sunfish will inhabit back water sloughs and such,

What do you all know about this?

I haven't fished the Mississippi at St Louis, but from what I have read, once you reach the areas above St Louis where the locks and dams exist there are some bass.  Most of what I have read suggested fishing around the wing dams, just below the water release of dams, and backwater sloughs.  I never heard of bass in the main channel but I guess if there were something for them to use as an ambush point to hide behind, it might be possible.

 

http://www.ifishillinois.org/profiles/Mississippi.php

 

This link describes each pool and they do have fishing reports at the end, including one for pool 26 at Alton which is just north of St Louis on the Illinois side.  There appears to be an error in the report because one line mentions catching largemouths up to 15 lbs on stinkbait.  I think they meant catfish because both the Illinois and Missouri largemouth records are between 13 and 14 lbs and who uses stinkbait for largemouths.  There does appear to be a report for largemouth in there though.  There is also a report for Woodriver which is just south of Alton.