I am from northern Utah and have River system near by called cuttler reservoir.  There are three different rivers that feed into this marshland of a lake.  The Bear River, Logan river feed into this.  The average water depth is about 4' and the channel being upwards of 18'  Most of it looks just like swamp.  I know that there is small mouth, Large mouth, crappie, walleye, carp, catfish in this river.  I am trying to get any information on how to narrow down to where the large and small mouth bass are located during this cold time of year.  Water temp is 39 degrees with usually zero visability.  There are many islands channels three bridges mainly cattail banks and muddy bottoms. It is a very slow moving river.  Just looking for any ideas or tips on how to up my catches in this dirty muddy river/lake.  Thanks.

To start off, cold muddy water is not good. Fishing will be tough, but it can be done. What I would do is look for some deep structure. That is  where the bass should be located, usually near a off shore humps and near points. Also, try to find warmer and clearer water. The fish will like these conditions more. Try draging a jig, or slow rolling a swim bait, or underpin. 

First of all, if the channel is 18 feet deep and the average depth is 4 feet, compared to the rivers I fish, that is pretty deep. In the shallow rivers I fish, 4 feet is a deep pool. When the water is that cold, smallmouth will still be in their winter holding spots. They will stack up in deeper slow moving water where they are very inactive. If you find that spot, you can drop baits all day long right on their heads and still not get bit. On a warm sunny day, some of the fish might get active and you'll need to be close to the winter spot as they may not travel very far. Be patient and wait till the water hits the mid to upper 40's and the action will pick up.