4tboys -
Big Daddy is partially correct. The adult fish did spawning last fall (November and December) and as with all salmon they died afterwords. However the next years group of fish are coming along. At this time of the year the fish tend to be scattered and difficult to pin down. Often the best concentration of Koks will be right on the surface - especially early mornings or calm days. They tend to be very boat shy so the best bet is troll with very long lines or planner boards.
A better option is wait for the water to warm some and the thermocline forms. This is concentrate the fish in a narrow band of water. On Stevens that usually begins in May depending on the weather (the warmer the spring the early the thermocline forms). At that time of year have to locate the proper depth by watching your depth finders or trail and error. You will find that the fish move deep as the day progresses as well as when the water temperature increases. Your gear selection is fine.
Stevens has larger fish than Roesiger. Other lakes with smallish koks include Whatcom and Baker. Larger but few fish can be found in Shannon, Samish, and American Lakes. Largest kokanee in the State are generally found in Roosevelt (NE Washington).
Catfish (brown bullheads) can be found in most of our bass lakes. Some to try would include Washington, Sammish, Cassidy, Stevens, Roesiger, Terrell, Wiser, and many of the smaller waters.
Good luck
Tight lines
Smalma