The Idaho Nymph is a phenomenal Steelhead and Rainbow fly. It represents a smaller black stonefly and has taken many a spooky trophy Steelhead. Also well known and trusted by a number of the Great Lakes fishermen. Lots of the Great Lakes rivers are just loaded with smaller stone flies so this offers a very good representation to present. fly used by both float and fly fishermen throughout North America. Idaho Nymphs imitates the Smaller Black Stonefly and the Damselfly nymph and are a killer Cutthroat and Rainbow pattern.