What It Is
Hexagenia limbata — Michigan's Most Famous Insect
The Hex is short for Hexagenia limbata, the largest mayfly in North America. With a body up to two inches long and a forked tail that doubles its length, a Hex dun floating on the surface is, as one guide once put it, "a floating filet mignon to a brown trout."
For most of its life — two full years — the Hex nymph lives burrowed into the soft muck on the river bottom, invisible and unfished. Then, over two to three weeks each June, millions of them crawl from the sediment, drift to the surface, and emerge as giant golden mayfly adults. The event is so dramatic, so concentrated, and so nutritionally significant to the trout that it triggers feeding behavior unlike anything else in the fly fishing year.
The largest brown trout in the river — fish that spend the rest of the season hiding in deep water and feeding at night — abandon their caution entirely during the Hex hatch. They move into the shallows, into the flat pools, into the riffles, and rise to the surface over and over again, gorging on Hex duns and spinners until the early hours of the morning. You can hear them. In the dark, on a flat Michigan river, the sound of a large brown trout rolling on a Hex is something you do not forget.
The most important fact about the Hex hatch
It happens almost entirely after dark. The first duns typically appear around 9:30–10pm when air temperatures stay above 65°F. The spinner fall — when mated females return to lay eggs and die on the water — peaks between 11pm and 2am. The fishing is essentially over by 3am. Plan accordingly.
Timing
When the Hex Hatch Happens in 2026
The Hex is one of the most weather-dependent hatches in fly fishing. There is no fixed calendar date — the hatch responds to water temperature and atmospheric conditions, not the calendar.
The Trigger Conditions
Three consecutive days of warm weather with air temperatures reaching 80°F during the day and staying above 65°F at night. Water temperature at or above 60°F — ideally 63–68°F. These conditions signal the nymphs to begin emerging. A cold front, rain, or a drop in night temperatures can pause the hatch for several days even mid-season.
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Early June — Muskegon & Pere Marquette
First Hex Activity
Michigan's mid-state rivers run warmer and see the first Hex activity 1–2 weeks ahead of the northern rivers. The Muskegon and Pere Marquette often produce the first meaningful Hex nights of the season. Look for lakes in northern Michigan to hatch first — river hatches follow 7–10 days later.
🪲
Mid June — Au Sable, Manistee, Boardman
Northern Rivers Begin
The Au Sable Holy Water, Upper and Lower Manistee, and Boardman River typically see the first Hex activity in mid-June. The hatch starts tentatively — sparse bugs, short windows — before building toward peak intensity. The last week of June is historically the peak on the Au Sable.
⭐
June 20 – July 4 — Peak Window
Prime Time Across All Rivers
The last week of June through the Fourth of July weekend is historically the most consistent window for heavy Hex activity statewide. Multiple rivers are firing simultaneously. This is when guided trips are essentially impossible to book without advance planning. The Au Sable peak is typically June 24–28.
🌙
July — Northern and UP Rivers
Late Season Extension
The Jordan, Rifle, Betsie, and Upper Peninsula rivers like the Fox and Two-Hearted see Hex activity running 2–3 weeks behind the Au Sable and Manistee. July Hex fishing on these less-pressured rivers can be exceptional. The Rifle River's late-June Hex is one of Michigan's most underfished events.
2026 Timing Note
The 2026 spring ran 3–4 weeks cold across Michigan — water temperatures were below normal well into late May. This means the Hex trigger conditions may arrive slightly later than a typical year. Monitor water temps on the major rivers starting June 10. When the Au Sable hits 62–65°F consistently, Hex activity is imminent within days.
Where to Fish
Best Michigan Rivers for the Hex Hatch
Not all rivers have Hex habitat. The nymph requires soft silt and muck bottom — the same slow, flat water that makes for difficult fly fishing the rest of the season becomes essential Hex real estate in June. Here is where to go.
Au Sable — Holy Waters
🏆 Elite
Peak: June 20–28
America's most famous Hex fishery. The flat, spring-fed pools between Stephan and Wakeley bridges hold enormous populations of Hex nymphs in the soft muck edges. The catch-and-release regulations protect the fish population — the largest browns in the state live here and show themselves for this hatch only.
Drift boat preferred
Flies only
C&R
Book early
View Au Sable conditions →
Manistee River — Lower
🏆 Elite
Peak: June 25 – July 5
The lower Manistee below Tippy Dam has spectacular Hex habitat in the slower sections above High Bridge and through the braided water near Tippy. The tailwater's consistent temperatures extend the Hex window. Less famous than the Au Sable but equally productive for large browns.
Drift boat ideal
Wading possible
Strong Hex population
View Manistee conditions →
Pere Marquette River
🏆 Elite
Peak: June 10–25
The PM's Hex season starts earlier than the northern rivers — often the first week of June in warm years. The slower sections between Indian Bridge and Sulak have excellent Hex habitat. Mike Batcke of Batcke's Fly Shop is a leading authority on PM Hex fishing; his guide dates fill by March.
First to peak
Drift boat recommended
Book by March
View PM conditions →
Muskegon River
⭐ Excellent
Peak: June 8–20
The Muskegon's wide, slow lower sections below Newaygo have significant Hex habitat. The tailwater runs warmer than northern rivers putting it among the first to see Hex activity each season. Big brown trout in the grassy bank edges go completely nocturnal during the hatch.
Early season
Large brown trout
Drift boat
View Muskegon conditions →
Peak: Late June – Early July
The Rifle's Hex hatch is one of Michigan's most underfished events. The Recreation Area pools have excellent soft-bottom Hex habitat and the fish are large and uncrowded. While everyone else is stacked on the Au Sable and Manistee, the Rifle fishes in near solitude.
Uncrowded
Wadeable
Underrated
View Rifle conditions →
Boardman River
⭐ Excellent
Peak: Late June
The Boardman's Hex hatch near Traverse City is excellent in the slower lower sections. A great option for anglers staying in the Traverse City area who want to avoid the three-hour drive to Grayling. The fish are large and the access is excellent.
Traverse City access
Wadeable
Less crowded than Au Sable
View Boardman conditions →
What to Bring
Gear & Fly Selection for the Hex Hatch
The Rod Setup
The Hex demands heavier gear than typical Michigan trout fishing. A 5–7 weight rod is appropriate — a 6-weight is the standard choice. You need to turn over large, air-resistant flies in the dark, often with a short quick cast rather than a long accurate one. A 9-foot 6-weight with a weight-forward line (sized 1.5 weights heavy to help turn over the big flies) and a 7–9 foot leader tapered to 1X or 2X is the standard Hex rig.
| Item | Recommendation | Why |
|---|
| Rod | 9ft 6-weight | Turns over large flies; handles big fish at night |
| Line | WF floating, sized 1.5 heavy | Aggressive taper helps turn over air-resistant Hex patterns |
| Leader | 7–9ft tapered to 1X | Short leader for night accuracy; strong enough for big fish |
| Tippet | 1X–2X nylon, 18–24 inches | Nylon floats better than fluorocarbon for dry Hex patterns |
| Net | Large rubber-mesh net | Oversized net for large fish; rubber mesh for dark releases |
| Headlamp | Red-light mode essential | Preserves night vision; white light spooks feeding fish |
| Waders | Chest waders with wading belt | Water levels can be high; wading belt is safety essential |
| Boots | Felt with studs or rubber with studs | Slippery wading in unfamiliar water at night |
| Hemostats | On a zinger, chest-height | You need to find them by feel in the dark for hook removal |
| Bug spray | DEET-based, applied before dark | June mosquitoes are severe on Michigan rivers after dark |
The Fly Box
The Hex hatch has three phases — emerger, dun, and spinner — each requiring a different pattern. Carry all three. Pinch the barbs on every fly before you start fishing. You will be releasing fish in the dark and barbless hooks save critical time and reduce stress on the fish.
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Hex Emerger
Size 4–6
Early hatch (9–10pm)
🦋
Hex Dun / Parachute
Size 4–6
Active hatch (10pm–midnight)
💀
Hex Spinner (Spent Wing)
Size 4–6
Spinner fall (midnight–2am)
🐭
Mouse Pattern
Size 2–4
Between rises (any time)
🟡
Foam Hex Pattern
Size 4–6
All stages — floats confidently in dark
🪲
Extended Body Hex
Size 4, 3XL hook
Finicky fish; exact imitation
Pro tip on fly selection
During the spinner fall, trout are most selective to spent-wing spinner patterns — the dead females lying flat on the surface are what the fish key on. But in the confusion of a heavy hatch, foam patterns and extended-body duns work almost as well and are far easier to see and track in the dark. Your local fly shop (Gates Lodge, Old Au Sable Fly Shop, Batcke's) will have exactly the right local patterns tied for their home water.
How to Fish It
Night Fishing Tactics for the Hex
Fishing the Hex hatch at night is unlike any other fly fishing experience — and it requires a completely different approach than daytime trout fishing.
🌙 The Night Fishing Playbook
🕙
Arrive before dark. Get to your spot and read the water while you can still see it. Find the flat pools, the soft muck edges, the foam lines. You need to know exactly where you are before the light goes. Walking an unfamiliar stretch of river in the dark without having scouted it first is a recipe for a swim.
👂
Listen before you cast. In the dark you fish by sound as much as by sight. The sound of a large brown rolling on a Hex is unmistakable — a deep, deliberate gulp rather than the delicate sip of a fish taking a small dry fly. When you hear a fish, wait and listen. Establish its rhythm. Find its location. Then cast.
🎯
Cast short, cast accurately. Accuracy matters more than distance at night. Cast to the sound of the rise — not where you think the fish is, but where you heard it. Most Hex anglers cast slightly upstream of the rise ring and let the fly drift through. Once you identify a quality fish, commit to that fish and don't move.
⏱
Be patient on the strike. The most common mistake in Hex fishing is striking too fast. A big brown trout takes a Hex slowly and deliberately. When you feel the take, pause — say "God save the Queen" — then set the hook. Striking immediately pulls the fly out of the fish's mouth before it has fully taken it.
🏃
Fight fast, release fast. Water temperatures during the Hex season are often 65°F or warmer — warm enough that prolonged fights seriously stress trout. Once you have a fish on, put maximum pressure on it, get it to the net quickly, keep it in the water, and release it without removing it from the river. A 20-inch brown can be landed and released in under two minutes.
🔦
Manage your headlamp religiously. Never shine your headlamp onto the water or in the direction of feeding fish. Use red-light mode only when handling flies or fish. A single blast of white light onto a flat pool can silence rising fish for 20 minutes. Experienced Hex anglers work entire nights without using white light on the water at all.
Sharing the River
Hex Hatch Etiquette — It Matters More Than You Think
The Hex hatch concentrates anglers on specific pools and flat water sections in a way that no other hatch does. During peak Hex season on the Au Sable, boat launches fill by 8pm. Common courtesy becomes essential when everyone is fishing in the dark within earshot of each other.
The Rules That Matter
Don't poach another angler's fish. If you hear a guide anchored on a pool with a client casting to a rising fish, do not wade or float into that water. Move to the next pool. This is the cardinal sin of Hex fishing and it happens every season.
Call out when floating past wading anglers. If you are in a drift boat, call out "drift boat coming through" before reaching wading anglers. They will step back. This courtesy prevents both confrontation and accidents in the dark.
Keep your light off the water. Even a brief phone screen flash 50 feet from a feeding fish can end the bite. If someone nearby shines a light on the water, say something politely — they may not realize what they are doing.
Don't thrash around in the water. Sound travels on a flat river at night. Heavy wading disturbs fish for a significant radius. Move slowly and deliberately to your spot and stay there.
Leave the launch cleaner than you found it. Boat launches in peak Hex season look like parking lots after a concert. Pack out your waste. Don't leave leaders and fly packaging on the ground.
Planning Your Trip
How to Book a Hex Hatch Trip
Guided Hex hatch trips on the Au Sable and Pere Marquette book out by March or April for the following June. If you are reading this in late May or June, call immediately — last-minute cancellations do open up, but plan as if they will not.
The Best Guides for the Hex
Gates Au Sable Lodge (Grayling) — The benchmark for Au Sable Hex fishing. Their guide staff has decades of experience on the Holy Water. Lodge accommodations available. gateslodge.com
Old Au Sable Fly Shop (Grayling) — One of the oldest fly shops in the country, operating on the Au Sable since 1936. Excellent guide service and the best local pattern selection for Hex fishing. oldausable.com
Batcke's Manistee River Fly Shop (Wellston) — Mike Batcke is the foremost authority on Pere Marquette Hex fishing. His June dates are essentially pre-booked by regular clients each year. schmidtoutfitters.com
Feenstra Guide Service (Muskegon) — The Muskegon's premier guide service. Their Hex trips on the lower river produce some of the largest browns of the season. feenstraguideservice.com
Booking timeline
For peak Hex season (June 20 – July 4): book by February. For early Hex on the PM and Muskegon (June 1–20): book by April. For late-season Hex on the Rifle, Boardman, and Jordan: June bookings often still available in May. If you cannot get a guide, self-guided Hex fishing is very productive — walk-in access on the Au Sable and wading access on most rivers is public.
What to Expect to Pay
Guided Hex float trips typically run $550–$700 for two anglers for a full evening session (usually 7pm until 2–3am). Half-night sessions are available on some rivers. The premium pricing reflects the late hours, the short season, and the consistently large fish. Most guides include all flies, leaders, and tippet. Bring your own rod, reel, waders, and headlamp.
→ Find a guide on Michigan Fly Fishing Hub's guide directory
FAQ
Frequently Asked Questions
Do I need a guide for the Hex hatch?+
No — but it helps significantly for first-timers. The learning curve for Hex fishing at night is steep. An experienced guide puts you on the right water at the right time, shows you how to read the rise, and teaches the strike timing. After one guided night, self-guided Hex fishing becomes much more productive. That said, walk-in access on the Au Sable and wading access on most Michigan rivers is public, and self-guided Hex anglers catch fish every night of the season.
What if the hatch doesn't happen when I arrive?+
This is the central frustration of Hex fishing. The hatch can pause for several days during a cold front or sustained rain. Even experienced anglers get skunked by the weather. The best strategy is to book multiple consecutive nights — the more nights you fish, the more likely you are to hit a good spinner fall. A week-long trip dramatically improves your odds over a single night. Monitor river temperatures closely: when the Au Sable or Manistee is holding above 63°F, Hex activity is likely that night.
What size fish can I expect during the Hex hatch?+
The Hex brings up fish that are invisible the rest of the season. On the Au Sable Holy Water, it is common to encounter brown trout in the 18–24 inch range during peak Hex nights. Fish over 24 inches are caught every season. The Pere Marquette and Muskegon produce similar size fish. The combination of large fly, darkness, and feeding aggression means that an angler who hits a good spinner fall has a realistic chance at the largest trout of their life.
Is a fishing license required for night fishing?+
Yes. A valid Michigan fishing license is required at all times including after dark. The standard annual resident license ($26) or non-resident license ($76) covers Hex fishing on all legal Michigan waters. Conservation Officers do check licenses during Hex season at popular launch sites and access points. See our
complete Michigan fishing license guide for details.
What rod weight should I use?+
A 9-foot 6-weight is the standard Hex rod. Some anglers prefer a 5-weight for the challenge on smaller water; some prefer a 7-weight on wide tailwaters like the Muskegon and Pere Marquette where casting a large fly into a downstream wind is common. The 6-weight strikes the best balance between casting large flies and handling fish delicately on fine tippet.
Can I fish the Hex hatch without a drift boat?+
Absolutely. Wading Hex fishing is highly effective on most rivers. On the Au Sable, wade anglers work specific known pools from a stationary position, listening for rises and casting to them. The key advantage of a drift boat is coverage — you can move through more Hex water in a night. Wading gives you intimate knowledge of a specific pool and can be more productive on nights when fish are concentrated in predictable spots.