Coldwater is a medium sized creek that is located west of Decorah. This is one of the few streams in Iowa where rainbow trout have been documented as naturally reproducing. Coldwater has many deep holes which make it an ideal place for bait fisherman. I remember going there as a kid with my grandpa and uncle. It always seemed that within minutes we'd have a fish hooked in one of the deep holes using worms, corn, or even cheese.
For the fly fisherman, Coldwater offers enough room to get your offering to where it needs to be. There isn't always room for a big backcast, but because of the twists and turns of this stream a long cast is rarely called for. Try running a nymph or streamer down the current and into the numerous undercut banks.
Again, for you spin fishermen, try a number five Rapala. Cast it upstream and retrieve it past fishy looking hides. Check out the document I've written detailing how to use shallow running crank baits to catch trout that are reluctant to strike your other offerings here. You can also do well letting a small jig run with the current through the numerous bank hides.