Au Sable River (Grayling/Mio) fishing conditions · Michigan

Now until 8 pmBrown trout

The bite peaks at 90. Water is 46°, inside their 45–68° range, and a solunar period lands on the window.

Right now: 90 for brown trout, go · inside the best windowTap or drag along the water to move through the next 36 hours

Brown trout, hour by hour

Each float is an hour. The deeper it rides, the better the bite. The strip underneath runs daylight, dusk and dark; the red rule marks the best window. Click any hour to read it.

904 pm
90
90
907 pm
80
80
8010 pm
80
80Sun
801 am
80
80
804 am
80
80
807 am
80
80
8010 am
80
80
801 pm
80
80
804 pm
80
80
777 pm
77
77
7710 pm
77
77Mon
801 am
80
80

Go, 85+Worth the trip, 70+Marginal, 55+Sit it out

Water: 46°F
Wind: 5 mph
Flow: 849 cfs
Light: Daylight
Sky: Partly Sunny
Air: 45°F
Barometer: Falling
Moon: 5% lit

What’s biting

Each species is scored against its own water-temperature range and tide preference, then wind, weather and warnings. The rules are Michigan regulations for these waters.

Brown trout

Salmo trutta

90GoNow until 8 pm

Water

46°

35°45–68° · ideal 55°78°

Why

Fish feed actively ahead of a pressure drop. Light breeze — ruffles the surface so fish spook less, and casting is easy. Inside brown trout's active range. Holds 3–25 ft down.

Keep

18" minimum · 2 a day

Catch and release only today. Artificial lures only; 2 trout a day, only 1 of them 18" or longer. Brown trout 18" minimum; kept only from the last Saturday in April to Sep 30.

Verified Oct 23, 2026 · Au Sable River, Mio power line to McKinley Bridge (gear restricted)

Last checked 15 days ago. Rules may have changed.

Season here: Apr–Oct, from this spot’s water-temperature record, 2023–2025. More on brown trout

Brook trout

Salvelinus fontinalis

90GoNow until 8 pm

Water

46°

30°40–65° · ideal 52°75°

Why

Fish feed actively ahead of a pressure drop. Light breeze — ruffles the surface so fish spook less, and casting is easy. Inside brook trout's active range. Holds 1–10 ft down.

Keep

7" minimum · 2 a day

Catch and release only today. Artificial lures only; 2 trout a day, only 1 of them 18" or longer. Brook trout 7" minimum; kept only from the last Saturday in April to Sep 30.

Verified Oct 23, 2026 · Au Sable River, Mio power line to McKinley Bridge (gear restricted)

Last checked 15 days ago. Rules may have changed.

Season here: Apr–May, Sep–Oct, from this spot’s water-temperature record, 2023–2025. More on brook trout

Rainbow trout

Oncorhynchus mykiss

90GoNow until 8 pm

Water

46°

35°45–68° · ideal 55°78°

Why

Fish feed actively ahead of a pressure drop. Light breeze — ruffles the surface so fish spook less, and casting is easy. Inside rainbow trout's active range. Holds 3–20 ft down.

Keep

10" minimum · 2 a day

Open. Keep fish within the limits. Artificial lures only; 2 trout a day, only 1 of them 18" or longer. Rainbow trout 10" minimum and may be kept all year.

Verified Oct 23, 2026 · Au Sable River, Mio power line to McKinley Bridge (gear restricted)

Last checked 15 days ago. Rules may have changed.

Season here: Apr–May, Sep–Oct, from this spot’s water-temperature record, 2023–2025. More on rainbow trout

Common carp

Cyprinus carpio

43Sit it outNo window clears the bar

Water

46°

42°52–86° · ideal 72°96°

Why

Fish feed actively ahead of a pressure drop. Light breeze — ruffles the surface so fish spook less, and casting is easy. Below common carp's active range (52–86°F). Holds 1–15 ft down.

Keep

no daily limit

Open. Keep fish within the limits. Michigan: "All others", carp included, have no size limit, no possession limit and are open all year. Live carp may not be used as bait.

Verified Oct 18, 2026 · Michigan

Last checked 20 days ago. Rules may have changed.

Season here: May–Sep, from this spot’s water-temperature record, 2023–2025. More on common carp

The water

Water temperature46°F
River849 cfs · steady · +1% in 24 h
Barometer30.04 inHg, falling

Sun, moon & solunar

Sunset today5:18 pm
Sunrise tomorrow7:23 am
MoonWaning crescent, 5% lit
Minor solunarToday 3:50 pm–4:50 pm
Major solunarTonight 10:30 pm–12:30 am
Minor solunarTomorrow 6:30 am–7:30 am

Solunar tables are a popular heuristic. A peer-reviewed test found they don’t predict catch on their own, so here they only nudge the score when the tide or moon already agree. How the score works

Fishing report

No current report covers these waters.

We only show reports an agency has published, with their date. Michigan DNR publishes a report for the state.

Licenses and rules: state fishery agencies · fish-consumption advisory

About this spot

The birthplace of Trout Unlimited and one of America's most storied trout rivers — the "Holy Water" above Mio is flies-only, no-kill, holding wild brook and brown trout. Below Mio Dam the river runs bigger, with an 18" minimum on browns. Steelhead and salmon runs stop at Foote Dam near Oscoda, far downstream. Live USGS flow and temperature near Red Oak.

Mio power line to McKinley Bridge: artificial lures only, 2 trout a day with only 1 over 18". Browns 18", rainbows 10", brook trout 7". Browns and brookies may be kept only from the last Saturday in April to Sep 30; rainbows all year. Upstream near Grayling the Holy Water (Burton's Landing to Wakeley Bridge) is flies-only and no-kill.

WaterRiver
AccessPier, shore and ramp
RulesMichigan
WhereOscoda County · 44.6611, -84.1056

Nearby

The closest public spots we cover, with the same 36 hours of floats.

Saginaw Bay57 mi · MichiganBest now until 8 pmSmall Craft Advisory

65Marginal

Port Crescent State Park68 mi · MichiganBest now until tomorrow 5 am

86Go

Manistee River95 mi · MichiganBest now until 8 pm

100Go

Pere Marquette River118 mi · MichiganBest now until 8 pm

84Worth the trip

Ludington State Park126 mi · MichiganBest now until 8 pm

90Go

Peninsula State Park (Nicolet Bay Beach)156 mi · WisconsinBest now until 7 pm

100Go

Questions people ask

Do I need a fishing license to fish at Au Sable River (Grayling/Mio)?

Yes (anglers age 16 and older). To fish at Au Sable River (Grayling/Mio) you need the appropriate state fishing license. See the agency's current rules: the state agency website

What fish are commonly targeted at Au Sable River (Grayling/Mio)?

Au Sable River (Grayling/Mio) is listed on this site for 4 commonly-targeted species: Brown Trout, Brook Trout, Rainbow Trout, Common Carp. Which species is currently in season and which is scoring highest today is shown in the per-species ranking on this page.

When is the best time to fish at Au Sable River (Grayling/Mio)?

It depends more on the species and the day's conditions than on a fixed "best hour." Water temperature, weather, and — at tidal locations — the stage of the tide drive activity most. The per-species ranking on this page scores every target species at Au Sable River (Grayling/Mio) against today's live conditions, so the fish near the top are your best bets right now; check back as conditions change through the day.

What kind of access does Au Sable River (Grayling/Mio) have?

Au Sable River (Grayling/Mio) has multiple access types — pier, shoreline, and at least one public boat ramp. Mio power line to McKinley Bridge: artificial lures only, 2 trout a day with only 1 over 18". Browns 18", rainbows 10", brook trout 7". Browns and brookies may be kept only from the last Saturday in April to Sep 30; rainbows all year. Upstream near Grayling the Holy Water (Burton's Landing to Wakeley Bridge) is flies-only and no-kill.

Which state's fishing regulations apply at Au Sable River (Grayling/Mio)?

state agency regulations apply at Au Sable River (Grayling/Mio). Size limits, creel limits, and seasonal closures are listed per species on each species page. Always confirm against the agency source linked from each regulation block — emergency closures can take effect mid-season.

Is Au Sable River (Grayling/Mio) tidal water?

No. Au Sable River (Grayling/Mio) is non-tidal — water level varies with rainfall, seasonal flow, and (where applicable) upstream dam releases rather than tidal exchange.