
Michigan · freestone
120 miles
Filled months are when that insect is on the chart. Best months for this river are lit.
Swipe months to stay on the year
| Insect | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hendrickson | ||||||||||||
| Caddis | ||||||||||||
| Hex (Hexagenia limbata) | ||||||||||||
| Brown Drake | ||||||||||||
| Trico | ||||||||||||
| Terrestrials |
Hatch-chart nymphs, dries, and streamers for this river. Not a crowdsourced catch report.
Open the Au Sable River fly list →3 listed points. Map is Vellum land and Teal water — a desk chart, not a satellite.
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Heart of the legendary Holy Water. Fly-fishing-only, catch-and-release. Classic Au Sable dry fly water with native brook and brown trout.
Upper river access with good brook trout water. Intimate, cedar-lined stream with excellent Hendrickson hatches in May.
Below Mio Dam for the lower Au Sable. Prime Hex hatch water with large brown trout. Night fishing during the Hex emergence is legendary.
Check Michigan DNR for current regulations. Holy Water section is fly-fishing-only, catch-and-release. Various sections have different gear and harvest restrictions.
Verify with Verify with the local fish and wildlife agency. Retrieved 2026-08-31. Seasons and gear rules change.
The Au Sable River in northern Michigan is the most storied trout stream in the Midwest, a sand-bottomed, spring-fed river that flows through jack pine forests and cedar swamps for nearly 120 miles before emptying into Lake Huron. The Au Sable's place in fly fishing history is secure: it was here that the conservation movement to protect wild trout gained early momentum, and the river's Holy Water section near Grayling, one of the first catch-and-release, fly-fishing-only waters in the country, became a model for wild trout management across the nation. The river supports healthy populations of brown and brook trout, with the upper sections favoring native brook trout and the middle and lower stretches holding larger browns.
The Au Sable's character is gentle and intimate, with soft currents, cedar-lined banks, and a sandy bottom that makes wading easy and pleasant. The river is also one of the finest canoe and drift boat rivers in the Midwest, with the traditional Au Sable river boat, a flat-bottomed wooden craft poled silently upstream against the current, providing a uniquely stealthy approach to rising fish. The Hendrickson mayfly hatch in May and the prolific Hex hatch in June and July, when massive Hexagenia limbata mayflies emerge at dusk and send large brown trout into feeding frenzies in the dark, are the seasonal highlights that draw anglers from across the country. The Hex hatch in particular is a nocturnal experience unlike anything else in American fly fishing, with anglers casting large dry flies by feel in near-total darkness to the explosive surface takes of trout they cannot see.
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Freestone
Brown Trout · Rainbow Trout · Steelhead
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Freestone
Brown Trout · Brook Trout
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Freestone
Brown Trout · Brook Trout · Steelhead

Freestone
Brown Trout · Brook Trout · Rainbow Trout
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Freestone
Brook Trout · Brown Trout
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Freestone
Brook Trout
If something here is thin or wrong, add what you know. It goes to review before it publishes.
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