West Rosebud Creek
Fly fishing in Montana · Intermediate · Best seasons: Summer, Fall
Target Species
Rainbow Trout, Brook Trout
About This Water
High country stream below Mystic Lake. Rainbow and brook trout in stunning alpine setting.
Fishing Recommendations
Welcome to the Beartooth Mountains. As your guide, I can tell you that West Rosebud Creek is one of Montana’s best-kept secrets for anglers who value scenery and high-action pocket water over trophy sizes. It is a quintessential alpine freestone stream that offers a "classic Montana" experience without the heavy drift-boat traffic of the nearby Yellowstone or Madison rivers.
🎣 Location Overview
West Rosebud Creek is located in the Custer Gallatin National Forest, south of the town of Fishtail. This drainage is carved by glacial action, characterized by crystalline water, massive granite boulders, and steep canyon walls.
What makes this water special is its diversity of character. It transitions from a tumbling mountain torrent above Emerald and Trout Lakes to a more classic meadow-style stream in the lower reaches. Because much of the upper creek is fed by the outflow of Mystic Lake (via a hydroelectric plant), the water temperatures remain colder and more stable than other regional streams, providing a sanctuary for trout during the heat of mid-summer. Anglers love it for the solitude and the "eager" nature of the fish.
🐟 Target Species & Behavior
The creek is a high-density fishery, meaning you will find plenty of fish, though they rarely exceed 14–16 inches.
- Rainbow Trout: These are the primary residents of the faster water. They are opportunistic and hardy. Look for them in the "seams" where fast water meets slow water, and in the bubbly oxygenated water at the heads of pools.
- Brook Trout: Found predominantly in the slower side channels, beaver ponds, and the calmer stretches near Emerald and Trout Lakes. They are stunningly colored here and highly aggressive toward dry flies.
- Behavior: Because the growing season is short at this elevation, these fish are not picky. They have a "see it and eat it" mentality. If a fly looks like food and is presented without drag, they will usually strike.
📅 Best Times to Fish
Optimal Seasons
- Summer (July – August): This is the prime window. Runoff usually subsides by early July. This is the peak of terrestrial and dry fly action.
- Fall (September – October): My personal favorite time. The Brook trout enter their spawning colors, the crowds disappear, and the Brown trout (found in the lower reaches) become more aggressive.
Best Times of Day
- 10:00 AM – 4:00 PM: In the high country, you don't need to be on the water at dawn. The bugs start moving once the sun hits the water and warms it up a few degrees.
Prime Conditions
Look for "bluebird" days for dry fly action, but don't shy away from a light overcast day in the fall, which can trigger a massive BWO (Blue Winged Olive) hatch.
🪰 Recommended Flies & Techniques
Top Fly Patterns
- Dry Flies:
- Royal Wulff or Royal Coachman (Size 12-16): A classic attractor that fish can see in broken water.
- Parachute Adams (Size 14-18): The gold standard for matching small mayflies.
- Chubby Chernobyl (Size 10-14): Perfect for the "Hopper-Dropper" rig in August.
- Elk Hair Caddis (Size 14-16): Tan or Olive.
- Nymphs:
- Bead-head Prince Nymph (Size 14-16): Irresistible to the local Brookies.
- Pheasant Tail (Size 16-18): For when the fish are being slightly more selective.
- Streamers:
- Woolly Bugger (Black or Olive, Size 8-10): Swing these through the deeper pools below the bridge crossings.
Effective Techniques
- High-Sticking / Tight-Line Nymphing: Because the creek is boulder-heavy, there are dozens of micro-currents. Keep as much fly line off the water as possible to prevent drag.
- The "Hopper-Dropper": Fish a large foam terrestrial on top and hang a small nymph (like a Copper John) 18 inches below it. This covers two zones of the water column simultaneously.
- Dry-and-Drip: In the clear pools, a stealthy approach and a long leader are key.
💡 Pro Tips & Local Knowledge
- The "Mystic" Factor: The flow of West Rosebud can be affected by the hydroelectric draw from Mystic Lake. If the water seems unusually high or low, it’s often due to the dam. Always check the USGS gauges if available.
- Focus on the "Pockets": Don't just fish the big pools. Some of the biggest Rainbows live in "pockets" the size of a hula-hoop behind large boulders.
- The Hike-In Payoff: Most people fish right next to the road near the campgrounds (Emerald Lake area). If you hike just a half-mile upstream from the Mystic Lake trailhead, the fishing pressure drops significantly and the fish become much less cautious.
- Bear Safety: This is Grizzly Country. Always carry bear spray, keep it accessible (not in your pack), and make noise while walking through thick brush along the creek.
⚠️ Important Information
- Access: Access is excellent via West Rosebud Road (Forest Service Road 72). There are several campgrounds (Pine Grove, Emerald Lake) that offer direct creek access.
- Regulations: You must have a valid Montana Fishing License and a Conservation License. Be sure to check the current FWP (Montana Fish, Wildlife & Parks) regulations, as specific catch-and-release rules or bait restrictions can change annually.
- Wading Safety: The rocks in West Rosebud are notoriously slick and often unstable. Felt soles or studded wading boots are highly recommended. A wading staff is a smart addition for the faster sections.
- Leave No Trace: This is a pristine wilderness area. Pack out all tippet scraps and trash.
Enjoy the crystal-clear water and the mountain air—West Rosebud is a place that reminds you why we pick up a fly rod in the first place. Tight lines!
Bug Hatches & Matching Flies
| Hatch | Type | Peak months | Time of day | Hook sizes | Matching flies |
|---|---|---|---|---|---|
| Blue Winged Olive (BWO) Baetis | mayfly | April, May, September, October | Late Morning/Afternoon | #18-22 | Parachute Adams #18-20, RS2 #20-22, BWO Sparkle Dun #18-20 |
| Salmonfly Pteronarcys californica | stonefly | June, July | All Day | #4-8 | Rogue Foam Stone #6-8, Pats Rubber Legs #4-8, Cat Puke #6 |
| Mother's Day Caddis Brachycentrus | caddis | May | Afternoon/Evening | #14-16 | Elk Hair Caddis #14-16, Peacock Caddis #14-16, LaFontaine's Deep Sparkle Pupa #14-16 |
| Pale Morning Dun (PMD) Ephemerella excrucians | mayfly | July, August | Morning/Early Afternoon | #16-18 | PMD Parachute #16-18, Pheasant Tail Nymph #16-18, Split Case PMD #16-18 |
| Golden Stonefly Hesperoperla pacifica | stonefly | July | Morning/Afternoon | #8-12 | Chubby Chernobyl #8-12, Golden Stone Nymph #10-12, Water Walker #10 |
| Spotted Sedge Hydropsyche | caddis | July, August | Late Afternoon/Evening | #14-18 | Goddard Caddis #14-16, Soft Hackle Hare's Ear #14-18, Iris Caddis #16 |
| Grasshoppers Orthoptera | terrestrial | August, September | Late Morning/Afternoon | #8-12 | Morrish Hopper #8-12, Dave's Hopper #10-12, Rainy's Grand Hopper #10 |
| Trico Tricorythodes | mayfly | August, September | Early Morning | #20-24 | Trico Spinner #20-24, Sunken Trico Spinner #22 |
| Midge Chironomidae | midge | March, April, October, November | Late Morning/Afternoon | #18-24 | Zebra Midge #18-22, Griffith's Gnat #18-22, Morgan's Midge #20-22 |