The Bighorn River is widely regarded as one of the premier fly fishing destinations in the United States. Known for its steady water flows, rich aquatic life, and thriving trout populations, it offers anglers an opportunity to experience world-class fishing. However, success on this river depends on one critical factor—choosing the right fly pattern. Since the Bighorn River supports a diverse range of insect hatches, trout feed selectively depending on the season, water conditions, and available food sources. For this reason, understanding which fly patterns work best throughout the year can significantly improve your catch rate. Whether you are an experienced angler or just starting out, having the right flies in your box will make a huge difference. Learn the top 10 fly patterns that consistently catch fish on the Bighorn River, with tips on when and how to use them.
Top 10 Fly Patterns
1. Zebra Midge
Best Season: Year-round
Best Use: Nymphing in slow-moving pools and tailouts
Why It Works:
Midges make up a significant portion of a trout’s diet, especially in colder months when other insects are scarce. The Zebra Midge is an effective subsurface pattern that imitates midge larvae and works exceptionally well in deep pools and slow-moving currents.
How to Fish It:
- Use a light indicator rig with a small weight to drift the fly naturally.
- Fish size 18-22 Zebra Midges in red, black, or olive.
2. Ray Charles Sowbug
Best Season: Fall, winter, and early spring
Best Use: Drifted along the river bottom where trout feed
Why It Works:
The Ray Charles Sowbug has become legendary on the Bighorn River because sowbugs are a dominant food source. Since the river is home to thousands of sowbugs, trout feed on them consistently, making this pattern a must-have.
How to Fish It:
- Fish it deep as a nymph with split shot to get it to the bottom.
- Use size 14-18 in tan, grey, or pink for the best results.
3. Pheasant Tail Nymph (PTN)
Best Season: Spring and summer
Best Use: Excellent BWO imitation for nymphing rigs
Why It Works:
This classic nymph mimics Blue-Winged Olive (BWO) nymphs, which are a staple in the trout diet. It’s an essential fly pattern for spring and summer when BWOs are most active.
How to Fish It:
- Drift under an indicator or use as a dropper under a dry fly.
- Size 14-18 works best on the Bighorn.
4. RS2 Emerger
Best Season: Spring and fall
Best Use: Drifted just below the surface during BWO hatches
Why It Works:
The RS2 Emerger is perfect for imitating mayflies struggling to emerge from the water’s surface, making it an excellent choice for when BWOs are hatching.
How to Fish It:
- Dead-drift in the surface film or swing slightly.
- Fish size 16-20 in grey, olive, or black.
5. Parachute Adams
Best Season: Summer and fall
Best Use: A go-to dry fly for rising trout
Why It Works:
The Parachute Adams is one of the most versatile dry flies available. Since it mimics mayflies and midges, it is an essential pattern for surface-feeding trout.
How to Fish It:
- Cast upstream to rising trout and let it drift naturally.
- Size 14-18 works best on the Bighorn.
6. CDC Caddis
Best Season: Late spring and summer
Best Use: Best fished dry during an evening caddis hatch
Why It Works:
Caddisflies are prolific on the Bighorn, and trout feed aggressively on them during the evening. The CDC Caddis is a high-floating dry fly that perfectly mimics the natural insect.
How to Fish It:
- Drift on the surface during an active hatch.
- Use size 14-18 in tan or olive.
7. Trico Spinner
Best Season: Summer
Best Use: For late-morning fishing when Trico hatches are abundant
Why It Works:
The Trico hatch happens in the mornings, and trout focus heavily on spent spinners. The Trico Spinner pattern perfectly matches these conditions.
How to Fish It:
- Use long, fine leaders for a natural presentation.
- Best in size 20-24.
8. Woolly Bugger
Best Season: Year-round
Best Use: Strip near banks or drift in deep runs
Why It Works:
The Woolly Bugger is a versatile streamer that imitates baitfish, leeches, and large nymphs. Because it triggers aggressive strikes, it is a go-to fly for catching larger trout.
How to Fish It:
- Strip in quick bursts near structure.
- Size 6-10 in black, olive, or brown works best.
9. Mysis Shrimp
Best Season: Year-round
Best Use: Best used below the dam where shrimp are abundant
Why It Works:
Mysis shrimp are a primary food source for trout below the dam. This fly pattern mimics drifting shrimp, making it a top-producing option in these areas.
How to Fish It:
- Fish deep using a nymph rig.
- Use size 14-18.
10. Bunny Leech
Best Season: Fall and winter
Best Use: Large, hungry trout will take this during cooler months
Why It Works:
The Bunny Leech is a large, meaty streamer that attracts aggressive brown trout in cold water conditions. This fly is perfect for anglers looking to target trophy fish.
How to Fish It:
- Strip slow and deep during cold months.
- Size 4-8 in black, olive, or purple.
Having the right flies is half the battle when fishing the Bighorn River. By selecting the best patterns for the season, you can match the hatch and increase your chances of landing more trout. Whether you are a beginner or a seasoned angler, these proven fly patterns will help you succeed.
For those looking to stock up on the best flies for the Bighorn River, visit the Bighorn Fly Shop for high-quality gear, expert recommendations, and everything you need for your next fishing adventure.