Lines for kings
You will likely be sight-fishing to Kings in shoals 1-3 feet deep. Floating line with some weight on the flies would be fine. You might check Schmidt Outfitters site. What river on the UP are you planning to fish? The Escanaba maybe? I you are fishing to spawners, make sure to fish to the bucks in the back (holding behind the hen) The bucks will not leave for long as long as the hen is there. If you "knock the lady off the barstool" (catch the hen) the bucks will leave! It is kind of repetitive, if you find the fish stay on them. Just keep drifting your fly through the males, eventually one will take.......then hold on!
Have fun, love the UP.