When is brown trout season in Montana?

Montana keeps brown trout open to fishing year-round for the 2026 regulation year — there is no closed season, though the daily bag and size limits below still apply every day.

What is the Montana bag limit for brown trout?

The Montana daily bag limit for brown trout is Part of the district combined-trout limit (brown + rainbow + golden + grayling, plus cutthroat in Central/Eastern): Western lakes 5 / day (only 1 over 22 in) + rivers 3 / day (only 1 over 14 in); Central lakes 5 + rivers 5 / day (only 1 over 18 in); Eastern lakes + rivers 5 / day. Beaverhead River browns 5 / day, all UNDER 18 in; Missouri below Holter Dam 3 / day, only 1 over 18 in and only 1 brown. The possession limit is 10 in possession combined trout (Western + Central lakes); 5 in possession Western/Central rivers. Some named waters set a different limit — check the water-body overrides above.

What size brown trout can you keep in Montana?

The Montana size rule for brown trout is No statewide minimum; Beaverhead River browns all must be under 18 in (max-size protection on big browns); 'only 1 over' large-fish caps on listed river reaches. Slot limit: Beaverhead River: brown trout 5 / day, all must be under 18 in (releases protect trophy browns); Missouri River Holter Dam to Cascade Bridge: 3 trout / day, only 1 over 18 in and only 1 may be a brown. Trophy rule: MT state-record brown trout 29 lb 0 oz Wade Lake 1966 (one of largest brown trout state records in the country, historically world-record-class); Beaverhead + Bighorn + Missouri + Madison tailwater brown trout produce 4-8 lb fish routinely with 10-12 lb fish landed annually; Bighorn + Beaverhead + Missouri + Madison brown-trout-fall-spawning-run mid-September through November is country's premier autumn streamer + leech fishing window; FWP does NOT stock brown trout on major blue-ribbon rivers (wild self-sustaining populations protected from hatchery genetic introgression).

Do you need a license to fish for brown trout in Montana?

Yes. Montana requires a valid fishing license to fish for brown trout, with the usual exemptions for young children, state free-fishing days, and some senior or disabled-veteran categories. A license is valid only in the state that issued it, so non-residents need a Montana license — compare resident and non-resident Montana fees on the state regulations page below.

Are there gear restrictions for brown trout in Montana?

Yes. In Montana, brown trout fishing carries these gear rules: Hook-and-line; trolling permitted; Live bait prohibited on most blue-ribbon trout streams; artificial-lures-only or fly-only on listed reaches; Barbless single hook required on listed catch-and-release reaches; Electric-motor-only special-regulation on Wade Lake + Cliff Lake; Conservation License + Fishing License required (AIS Prevention Pass required for anglers 16+): $8 res Conservation + $21 res season fishing + $2 res AIS / $10 NR Conservation + $100 NR season fishing + $7.50 NR AIS; Confirm current-year FWP Fishing Regulations for District-by-District TROPHY MANAGEMENT reach + season list.

Do specific Montana waters have different brown trout rules?

Yes. 6 named Montana waters carry rules that override the statewide brown trout regulation, including Beaverhead River, Wade Lake + Cliff Lake, Bighorn River, and 3 more. See the named water-body overrides above for the exact rule on each.

2026 regulation year

Montana Brown trout 2026 — Season, Bag Limit, Size Rules

Salmo trutta

Last updated June 8, 2026

Montana brown trout fishery is the country's premier wild + naturally-reproducing brown trout destination in the lower 48 — Montana brown trout were introduced from German + Loch Leven stock in 1889 (Madison River + Madison Hatchery — one of the earliest documented brown trout introductions in the country) and now support wild naturalized populations on every blue-ribbon trout river statewide with no stocking required. The headline trophy brown trout waters: the Beaverhead River (80-mile tailwater from Clark Canyon Reservoir at Dillon MT through Barretts + Pipe Organ + Beaverhead Canyon + Twin Bridges — country's premier trophy brown trout tailwater, 4-8 lb fish routinely with 10+ lb fish landed annually); the Bighorn River (Yellowtail Dam tailwater 13-mile blue-ribbon reach from Fort Smith MT downstream — produces 4-8 lb brown trout routinely with 12+ lb fish landed annually); the Missouri River below Holter Dam (40+ mile blue-ribbon tailwater — wild brown trout to 10+ lb consistently); the Madison River (183-mile river — wild brown trout to 8+ lb on '50-mile riffle' below Quake Lake); the Big Hole River + Ruby River + Boulder River + Jefferson River + Yellowstone River through Paradise Valley + Livingston. Wade Lake + Cliff Lake (Beaverhead County natural lakes adjacent to the Madison River — country's premier still-water trophy brown trout fishery) hold the MT state-record brown trout 29 lb 0 oz Wade Lake 1966 — one of the largest brown trout state records in the country (and historically world-record-class). The Bighorn tailwater + Beaverhead + Missouri + Madison brown-trout-fall-spawning-run is the country's premier autumn streamer + leech fishing window (mid-September through November). The Beaverhead River caps browns at 5 / day all under 18 in (protecting trophy browns) + the Missouri below Holter Dam at 3 / day with only 1 over 18 in — Montana protects big browns with 'only 1 over' caps + catch-and-release reaches, not minimum-length limits. FWP does NOT stock brown trout on the major blue-ribbon rivers — wild self-sustaining populations are deliberately protected from hatchery genetic introgression. Open year-round on most waters.

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Season

Open year-round Open year-round on most waters; quality-management waters carry seasonal closures; Beaverhead + Big Hole + Bighorn + Missouri + Madison + Wade Lake wild brown-trout reaches managed under FWP wild-trout regulation (Beaverhead browns all under 18 in; the lower Big Hole + parts of the Beaverhead catch-and-release).

Bag & possession

Daily bag: Part of the district combined-trout limit (brown + rainbow + golden + grayling, plus cutthroat in Central/Eastern): Western lakes 5 / day (only 1 over 22 in) + rivers 3 / day (only 1 over 14 in); Central lakes 5 + rivers 5 / day (only 1 over 18 in); Eastern lakes + rivers 5 / day. Beaverhead River browns 5 / day, all UNDER 18 in; Missouri below Holter Dam 3 / day, only 1 over 18 in and only 1 brown
Possession: 10 in possession combined trout (Western + Central lakes); 5 in possession Western/Central rivers

Size, slot, trophy rules

Size: No statewide minimum; Beaverhead River browns all must be under 18 in (max-size protection on big browns); 'only 1 over' large-fish caps on listed river reaches
Slot: Beaverhead River: brown trout 5 / day, all must be under 18 in (releases protect trophy browns); Missouri River Holter Dam to Cascade Bridge: 3 trout / day, only 1 over 18 in and only 1 may be a brown
Trophy rule: MT state-record brown trout 29 lb 0 oz Wade Lake 1966 (one of largest brown trout state records in the country, historically world-record-class); Beaverhead + Bighorn + Missouri + Madison tailwater brown trout produce 4-8 lb fish routinely with 10-12 lb fish landed annually; Bighorn + Beaverhead + Missouri + Madison brown-trout-fall-spawning-run mid-September through November is country's premier autumn streamer + leech fishing window; FWP does NOT stock brown trout on major blue-ribbon rivers (wild self-sustaining populations protected from hatchery genetic introgression)

Gear restrictions

Hook-and-line; trolling permitted
Live bait prohibited on most blue-ribbon trout streams; artificial-lures-only or fly-only on listed reaches
Barbless single hook required on listed catch-and-release reaches
Electric-motor-only special-regulation on Wade Lake + Cliff Lake
Conservation License + Fishing License required (AIS Prevention Pass required for anglers 16+): $8 res Conservation + $21 res season fishing + $2 res AIS / $10 NR Conservation + $100 NR season fishing + $7.50 NR AIS
Confirm current-year FWP Fishing Regulations for District-by-District TROPHY MANAGEMENT reach + season list

Named water-body overrides

Where statewide rules differ on specific Montana waters:

Beaverhead River
Brown trout 5 / day, all must be UNDER 18 in (large-fish protection); Clark Canyon Dam to High Bridge FAS + Barretts Diversion to the mouth catch-and-release only; 4-8 lb fish routinely with 10+ lb fish landed annually
Wade Lake + Cliff Lake
Combined trout under the Central District lake standard (5 / day, 10 in possession); MT state-record brown trout 29 lb 0 oz Wade Lake 1966; electric-motor-only watercraft, spawning channel closed as posted
Bighorn River
Combined trout under the Central District river standard; 4-8 lb brown trout routinely with 12+ lb fish landed annually
Missouri River below Holter Dam
Holter Dam to Cascade Bridge 3 trout / day, only 1 over 18 in and only 1 may be a brown; wild brown trout to 10+ lb; fall-spawning-run mid-September through November
Madison River
Quake Lake outlet to Varney Bridge ALL trout CATCH-AND-RELEASE, artificial lures only, wade-only (no boats); brown trout to 8+ lb on the wild-trout reaches
Big Hole River
Headwaters to Dickie Bridge combined trout 5 / day no size restriction; Dickie Bridge to the mouth catch-and-release only (Apr 1 – Sept 30)

Official source

Montana Fish, Wildlife & Parks (FWP) publishes the authoritative 2026 Montanafishing regulations. Always verify the current rule before fishing — emergency closures and in-season changes can override what's published here.

Visit official Montana fishing regulations →

Emergency-order channel

Brown trout closures, slot-limit changes, and harvest pauses are posted to Montana Fish, Wildlife & Parks's emergency-order feed — check it before any Montana trip during the active season.

Frequently asked questions

When is brown trout season in Montana?: Montana keeps brown trout open to fishing year-round for the 2026 regulation year — there is no closed season, though the daily bag and size limits below still apply every day.
What is the Montana bag limit for brown trout?: The Montana daily bag limit for brown trout is Part of the district combined-trout limit (brown + rainbow + golden + grayling, plus cutthroat in Central/Eastern): Western lakes 5 / day (only 1 over 22 in) + rivers 3 / day (only 1 over 14 in); Central lakes 5 + rivers 5 / day (only 1 over 18 in); Eastern lakes + rivers 5 / day. Beaverhead River browns 5 / day, all UNDER 18 in; Missouri below Holter Dam 3 / day, only 1 over 18 in and only 1 brown. The possession limit is 10 in possession combined trout (Western + Central lakes); 5 in possession Western/Central rivers. Some named waters set a different limit — check the water-body overrides above.
What size brown trout can you keep in Montana?: The Montana size rule for brown trout is No statewide minimum; Beaverhead River browns all must be under 18 in (max-size protection on big browns); 'only 1 over' large-fish caps on listed river reaches. Slot limit: Beaverhead River: brown trout 5 / day, all must be under 18 in (releases protect trophy browns); Missouri River Holter Dam to Cascade Bridge: 3 trout / day, only 1 over 18 in and only 1 may be a brown. Trophy rule: MT state-record brown trout 29 lb 0 oz Wade Lake 1966 (one of largest brown trout state records in the country, historically world-record-class); Beaverhead + Bighorn + Missouri + Madison tailwater brown trout produce 4-8 lb fish routinely with 10-12 lb fish landed annually; Bighorn + Beaverhead + Missouri + Madison brown-trout-fall-spawning-run mid-September through November is country's premier autumn streamer + leech fishing window; FWP does NOT stock brown trout on major blue-ribbon rivers (wild self-sustaining populations protected from hatchery genetic introgression).
Do you need a license to fish for brown trout in Montana?: Yes. Montana requires a valid fishing license to fish for brown trout, with the usual exemptions for young children, state free-fishing days, and some senior or disabled-veteran categories. A license is valid only in the state that issued it, so non-residents need a Montana license — compare resident and non-resident Montana fees on the state regulations page below.
Are there gear restrictions for brown trout in Montana?: Yes. In Montana, brown trout fishing carries these gear rules: Hook-and-line; trolling permitted; Live bait prohibited on most blue-ribbon trout streams; artificial-lures-only or fly-only on listed reaches; Barbless single hook required on listed catch-and-release reaches; Electric-motor-only special-regulation on Wade Lake + Cliff Lake; Conservation License + Fishing License required (AIS Prevention Pass required for anglers 16+): $8 res Conservation + $21 res season fishing + $2 res AIS / $10 NR Conservation + $100 NR season fishing + $7.50 NR AIS; Confirm current-year FWP Fishing Regulations for District-by-District TROPHY MANAGEMENT reach + season list.
Do specific Montana waters have different brown trout rules?: Yes. 6 named Montana waters carry rules that override the statewide brown trout regulation, including Beaverhead River, Wade Lake + Cliff Lake, Bighorn River, and 3 more. See the named water-body overrides above for the exact rule on each.

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