The Gallatin in the Canyon is pretty clear of ice and fishing has been good. Midges will be your main hatch to match. We have been fishing various small flashy nymphs, perdigons, hare's ears, prince nymphs and stoneflies. Bigger white streamers imitate the baby whitefish and sucker minnows well. Small natural streamers such as a Sculpzilla, bellyache or McCunes have been working great for us as well.
Dries:
Baetis and midges
Nymphs:
perdigons, hare's ears, prince nymphs, zebra midges, rainbow warriors, $3 Dips
Streamers:
Sculpzilla, bellyache or McCunes, buggers