Slough Creek
Fly fishing in Montana · Advanced · Best seasons: Summer, Fall
Target Species
Cutthroat Trout
About This Water
Just north of Yellowstone Park boundary. World-class cutthroat fishing in meadow water.
Fishing Recommendations
Slough Creek is widely considered one of the "Holy Grail" destinations for fly anglers worldwide. Located in the northeastern corner of Yellowstone National Park, it offers a quintessential meadow-creek experience. This is technical, sight-fishing heaven where the scenery is as breathtaking as the trout are discerning.
🎣 Location Overview
Slough Creek is a classic high-country meadow stream characterized by its slow, meandering curves, deep undercut banks, and gin-clear water. What makes it special is the combination of spectacular wildlife (it’s prime wolf and grizzly territory) and highly technical dry fly fishing.
The creek is divided into the "Lower Meadows" (near the campground) and the "Upper Meadows" (accessed by hiking or horse packing). The water moves at a "walking pace," meaning every ripple or splash is visible. Anglers love it because it rewards patience, stealth, and perfect presentations. It is not a place for high numbers; it is a place for quality stalks and rewarding catches.
🐟 Target Species & Behavior
The primary inhabitant is the Yellowstone Cutthroat Trout.
- Behavior: These fish are notorious for being "surface-oriented" but highly suspicious. Because the water is so flat and clear, they have plenty of time to inspect your fly.
- Holding Patterns: Look for them in the "tail-outs" of pools, tucked tightly against undercut banks, or suspended in the "seams" where slow and slightly faster water meet.
- Feeding: They are opportunistic but selective. During a hatch, they will lock onto a specific life stage of an insect. In the absence of a hatch, they are suckers for high-protein terrestrials (grasshoppers, beetles, ants).
📅 Best Times to Fish
- Optimal Months: Early July through late September.
- July: The water drops and clears after runoff. This is prime time for Drake and Mayfly hatches.
- August: The "Dog Days" bring world-class terrestrial fishing.
- September: Cooler mornings and the arrival of Blue Winged Olives (BWOs).
- Best Time of Day: 10:00 AM to 4:00 PM. Unlike many rivers where early morning is best, Slough Creek relies on the sun to warm the water and activate insect life (especially terrestrials).
- Conditions: A slight breeze can actually be your friend here, as it puts a "riffle" on the water's surface, making it harder for the fish to see you or your leader.
🪰 Recommended Flies & Techniques
Top Fly Patterns
- Dries:
- Green Drake (Size 10-12): Critical in early July.
- PMDs (Size 16-18): Pale Morning Duns are a staple.
- Parachute Adams (Size 14-20): The ultimate "searching" pattern.
- Terrestrials:
- Morrish Hopper (Size 10-14): Tan or Pink/Peach bellies.
- Ants/Beetles (Size 16-18): A "Chernobyl Ant" is often too big; go subtle with a Cinnamon Ant.
- Nymphs:
- Pheasant Tail (Size 16-20): Dropped 18 inches behind a dry fly.
- Zebra Midge (Size 18-22): For deep pools.
Techniques
- The "Reach Cast": This is essential. You must be able to place your fly upstream of the fish while keeping your fly line out of their field of vision.
- Dry-Dropper: A small hopper with a tiny, unweighted nymph behind it is the most effective way to cover ground in the meadows.
- Stealth: You must stay low. Sometimes you literally have to crawl to the bank on your knees to avoid "spooking" the pool.
💡 Pro Tips & Local Knowledge
- The Three Meadows:
- First Meadow: Easy access, most crowded.
- Second Meadow: A 5-mile hike. Fewer people, larger fish on average.
- Third Meadow: For the dedicated. Requires a long hike or overnight pack trip. The solitude here is unmatched.
- The "Slough Creek Sip": Cutthroats don't usually "smash" a fly; they rise slowly and "sip" it. Count "one-Mississippi" before setting the hook to ensure the fish has closed its mouth and turned its head down.
- Long Leaders: Use a 9-foot to 12-foot leader tapered to 5X or even 6X. Fluorocarbon tippet is recommended for its low visibility in the crystal-clear water.
⚠️ Important Information
- Access: Located via the Northeast Entrance Road (near Silver Gate/Cooke City). The trailhead starts near the Slough Creek Campground.
- Permits: You must have a Yellowstone National Park Fishing Permit (a Montana state license is not valid here). You can buy these at park visitor centers or fly shops in Gardiner/West Yellowstone/Cooke City.
- Bear Safety: This is Grizzly Country. You are required to carry bear spray, keep it accessible (not in your pack), and know how to use it. Never fish alone if possible, and make noise while walking through willows.
- Regulations: Slough Creek is Catch and Release only for Cutthroat Trout. Only lead-free tackle and barbless hooks are permitted. Felt-soled wading boots are banned in the park to prevent the spread of invasive species.
Bug Hatches & Matching Flies
| Hatch | Type | Peak months | Time of day | Hook sizes | Matching flies |
|---|---|---|---|---|---|
| Western Green Drake Drunella doddsii | mayfly | July | Afternoon | #10-12 | Hair Wing Green Drake #10-12, Green Drake Cripple #12, Picket Pin #10-12 |
| Pale Morning Dun (PMD) Ephemerella spp. | mayfly | July, August | Late Morning to Afternoon | #16-20 | Sparkle Dun #16-18, PMD Emerger #16-20, Pheasant Tail #16-18 |
| Blue Winged Olive (BWO) Baetis spp. | mayfly | May, September, October | Mid-day | #18-22 | RS2 #20-22, Parachute Adams #18-22, WD-40 #20-22 |
| Grasshoppers Orthoptera | terrestrial | August, September | Late Morning to Evening | #8-14 | Morrish Hopper #10-12, Dave's Hopper #8-14, Thunder Thighs Hopper #12 |
| Yellow Sally Isoperla spp. | stonefly | July, August | Afternoon to Evening | #14-16 | Yellow Sally Chubby Chernobyl #14, Iron Lotus #16, Stimulator #14-16 |
| Trico Tricorythodes spp. | mayfly | August, September | Early Morning | #22-26 | Trico Spinner #22-24, Sunken Trico Spinner #22, Drowned Trico #24 |
| Spotted Sedge Hydropsyche spp. | caddis | July, August | Evening | #14-18 | Elk Hair Caddis #14-16, LaFontaine's Deep Sparkle Pupa #16, X-Caddis #16-18 |
| Black Ants and Beetles Formicidae / Coleoptera | terrestrial | July, August, September | All Day | #14-20 | Cinnamon Ant #16-18, Foam Beetle #14-16, Flying Ant #16 |