According to the compendium in game "Steelhead Trout populations are dotted around various lakes, mostly in the south. Steelhead Trout respond to many types of bait, most especially worms. They are fairly large and good to eat. Bigger specimens can be quite powerful and strongly resist being reeled in. They are notably more active in rainy weather. A few hardy fishermen in the northern Roanoke Valley claim to have seen, but never managed to catch, a Legendary Steelhead Trout."
According to the compendium in game "Worms are the best bait to successfully catch trout"