Trout are a lot like humans: When it gets cold out, they tend to get lazy. This is especially true in mountain streams, where they go nearly dormant in cold weather. Fly anglers are better off fishing tailwaters (the sections of rivers just below the dam of a reservoir), and the Arkansas River Tailwater boasts the best winter fishery in the state. In fact, the Arkansas actually fishes better in winter than in summer. Nymphing is the can't-lose tactic here, but keep your eye out for dry-fly hatches. If you're willing to brave the cold, expect to hook sixteen- to twenty-inch rainbows. Looking to target warm-water species? The Pueblo Reservoir is a great spot for walleye, wiper, catfish, bass and crappie.