Montana

Bighorn River Fishing Forecast

World-class tailwater with 2000+ trout per mile and year-round stable temps 38-66F

In SeasonHigh confidence

Open year-round (check section regs)

Central District - rivers open year-round unless specified. Blue-ribbon fishery

Limit: 3 trout combinedGear: Check special regs by section
View full regulations

Today's Fishing Conditions

4/10

Fair

Updated 6:32 PM

Water Temp

39°F

Flow Rate

1780 CFS

Best Time

2 AM - 4 AM

Top Fly

WD-40

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Quick Facts

Species

Brown Trout and Rainbow Trout

River Type

tailwater

March Water Temp

40°F - 48°F

March Fishing Tactics

Primary Targets

Rainbow TroutBrown Trout

Recommended Tactics

BWOsMidgesEarly PMDs

Prime BWO season begins. Overcast days best.

March Hatches

BWO

Mayfly

Primary
42-55°FPeak: 1PM

Year-round tailwater BWO fishing. Spring and fall prime. Overcast days best.

Midge

Midge

Primary
38-50°FPeak: 12PM

Year-round midge fishing. Zebra Midges, Disco Midges, RS2. Critical winter pattern.

Scud

Crustacean

Primary
38-66°FPeak: 10AM

Year-round subsurface staple. Pink, gray, olive scuds essential.

Sowbug

Crustacean

Primary
38-66°FPeak: 10AM

Year-round nymphing. Ray Charles, Miracle Nymph patterns.

San Juan Worms

Aquatic Worm

38-66°FPeak: 10AM

After rain events most effective. Red, pink, brown colors.

Year-Round Fishing Guide

MonthWater TempTactics
January38-45°FMidges, BWOs, Scuds, Sowbugs
February38-46°FMidges, BWOs, Scuds
March(Now)40-48°FBWOs, Midges, Early PMDs
April42-50°FBWOs, Midges, PMD nymphs
May45-52°FBWOs, PMDs, Caddis
June48-55°FPMDs, Caddis, Tricos starting
July50-58°FPMDs, Tricos, Caddis
August50-60°FTricos, PMDs, Hoppers
September48-56°FBWOs, Tricos, Streamers
October45-52°FBWOs, Midges, Streamers
November42-48°FBWOs, Midges, Scuds
December38-45°FMidges, BWOs, Scuds, Sowbugs

Spawning Seasons

Please respect spawning fish and their redds. Avoid fishing over actively spawning trout.

Brown Trout

Spawn months: October, November

Night spawning common. Males become very dark with pronounced kype during spawn.

Rainbow Trout

Spawn months: March, April

Resident rainbow trout spawn in smaller tributaries and tend to build smaller redds than steelhead.

Access Points & Parking for Bighorn River

Afterbay Dam

Immediately below dam - trophy water.

Facilities:Parking, Boat Launch
Best for:Trophy trout

Three Mile

Most popular access point.

Facilities:Parking, Boat Launch, Restrooms
Best for:Float fishing

Thirteen Mile

Mid-river access.

Facilities:Parking, Boat Launch
Best for:Extended floats

Bighorn

Lower river access near town.

Facilities:Parking, Town Services, Boat Launch
Best for:Full-day floats

How to Fish Bighorn River: Tips & Tactics

The Bighorn River is one of America's legendary tailwaters, producing trophy brown and rainbow trout in incredible numbers. Fish counts consistently exceed 5,000 trout per mile.

Best Times of Day

Year-round fishing is excellent due to stable dam releases. Midge and mayfly hatches occur daily. The river fishes well even in challenging conditions.

Recommended Techniques

Float fishing is the primary method. Match the prolific midge, sowbug, and mayfly hatches. Nymphing is highly effective. Dry fly fishing during hatches.

Water Conditions

Dam releases create perfect conditions year-round. Water clarity is excellent. The Bighorn is consistent and productive.

Fly Selection

Sowbugs and scuds are essential. Midge patterns in sizes 18-22. San Juan Worms year-round. PMDs and BWOs for mayflies.

Local Knowledge

The first three miles below the dam are the most productive. Crow Reservation regulations may apply. Float fishing is the tradition.

Local Tips

Fort Smith is the primary destination. The Bighorn produces trophy fish consistently. This is bucket-list fishing.

When is the Best Time to Fish Bighorn River?

Spring

Excellent fishing with increasing hatches.

Summer

PMD and caddis hatches. Fish throughout the day.

Fall

Brown trout become aggressive. Trophy season.

Winter

Year-round tailwater stays productive. Midge focus.

Recommended Equipment for Bighorn River

Rod

9-foot, 5-weight is standard.

Line

Floating line for most fishing.

Leader & Tippet

9-12 foot leaders, 5X-6X tippet.

Waders

Breathable waders. Cold water year-round.

Essential Flies

SowbugScudSan Juan WormPMDMidge

Bighorn River Fishing Regulations

Season

Open year-round.

Limits

Check Montana FWP for current regulations.

Special Regulations

First 3 miles have special regulations.

Bait Restrictions

Artificial flies and lures only.

Notes

The Bighorn flows through Crow Reservation - respect tribal regulations.

Always verify current regulations with Montana fish and wildlife agency before fishing. Regulations can change annually.

Fly Shops & Guides Near Bighorn River

Local Fly Shops

  • Bighorn Angler - Fort Smith
  • Cottonwood Camp
  • Bighorn Trout Shop

Guide Services

  • Bighorn Angler Guides
  • Cottonwood Camp Guides
  • Bighorn River Guides

Optimal Fishing Conditions

Optimal Flow

2500 - 5000 CFS

Best fishing conditions

Optimal Water Temperature

45° - 55°F

Ideal for active trout

Other Montana Trout Rivers

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