The following report is by Rising Trout Flyfishing Outfitters:
Current Flow: ~ 376 CFS @ Gallatin Gateway
Winter is starting to settle into the Gallatin this week, with cooler temps, shorter windows of warmth, and the first rounds of light snow in the forecast. Overnight lows are dipping well below freezing, so most early hours are slow and icy. The most productive fishing continues to fall in that late-morning to midafternoon window when the valley finally thaws a bit and trout slide out of their deepest holding water.
Nymphing is the clear staple right now. Small baetis and midge patterns paired with a jigged stonefly or slim attractor are producing in the soft buckets, deeper troughs, and slower inside bends. Expect fish to stay glued to winter water—anything slow, deep, and consistent—especially in canyon stretches where the sun doesn’t hit until later. Take your time getting flies down; subtle winter eats are common, and adjusting weight makes all the difference.
There are still occasional surprises on warmer afternoons. A brief midge cluster or tiny BWO trickle can spark a short-lived dry-fly window, mainly in the valley where the river opens up. Streamer fishing is more hit-or-miss as water temps drop, but during mild spells or in lower-gradient stretches, a slow, low-and-tight presentation can still move a fish or two.
Winter fishing has officially begun on the Gallatin—bundle up, fish smart, and focus on the warmest hours for the best action..
Recommended Flies:
Nymphs: Perdigon #16–18, Zebra Midge #18–20, Micro May #18, WD-40 #18–20, Frenchie #18, Soft Hackle PT #16–18, Eggs #12, Pat’s Rubberlegs #10–14, Jigged Rubberlegs #12–14
Streamers: Mini Sculpin, Thin Mint, Sculpzilla, Small Sparkle Minnow
Dries: Griffith’s Gnat #18–20, BWO Cripple #18–20, Extended Body BWO #18
Tactics: Slow down and fish methodically. Depth and weight matter on the Gallatin — adjust until you’re ticking bottom in the deeper slots. Early in the day, target slow wintering water. As temperatures rise, work into soft riffles and mid-depth seams where trout slide up to feed. If you’re tossing streamers, keep retrieves slow and tight to structure.
Photo credit: Louis Gaudet from Getty Images
