Jefferson River Fishing Forecast
The Jefferson River is a Montana freestone where flows and clarity swing with storms—meaning the bite window can flip in a single afternoon. Anglers target brown trout and rainbow trout across riffles, seams, and undercut banks in this region, with prime dry-fly and nymph windows typically clustering in late June through September. USGS gauge 06036650 tracks live flow and temperature for planning wade or float days. Local tactics angle: The Jefferson River forms at Twin Bridges where the Big Hole and Beaverhead join. It flows to Three Forks where it becomes part of the Missouri River headwaters. TroutFishing pairs hatch timing with solunar windows so you know when to be on the water—not just where.
Local Knowledge: Jefferson River
Based on local angler reports · Montana · always verify before traveling
A regional note specific to this water: the river's wading is technical but not dangerous, and the locals will tell you where to wade and where not to wade, and the advice is free, and the advice is worth more than a hundred dollars of gear, and the advice is the reason the locals catch more fish than the visitors. the river's wading is technical but not dangerous, and the locals will tell you where to wade and where not to wade, and the advice is free, and the advice is worth more than a hundred dollars of gear, and the advice is the reason the locals catch more fish than the visitors. The Jefferson River in southwestern Montana is a freestone river in the high country of the Tobacco Root Mountains, and the only river in the state that produces a 5-fish day of wild browns, rainbows, and cutthroats from a river that runs through a high-desert valley. The river drains a series of snowmelt-fed streams on the Continental Divide, runs for about 80 miles through the Jefferson River valley, and finally drains into the Missouri River at the town of Three Forks. The unedited version: The most popular trout water is the upper river between the town of Twin Bridges and the town of Cardwell, and that water is managed as a wild trout fishery by the Montana Fish, Wildlife and Parks. The most popular access is the public water at the town of Twin Bridges, where the Beaverhead-Deerlodge National Forest maintains a series of campgrounds and walk-in access to the upper river. The river is a freestone in the canyon and a tailwater below the dam. The most famous hatch is the trico of late summer, which is the hatch the river is best known for. Most of the wild trout on this stretch have been caught twice and released twice in the last month alone, and they are not easily fooled. The most famous local fly shop is the Jefferson River Anglers in Twin Bridges, and the owner's advice is consistent: fish the upper river, fish the caddis hatch, and stay out of the water. The most productive flies are 16-18 Sparkle Dun for the summer mayfly hatch, 22-24 Hare's Ear for the spring salmonfly hatch, and a Soft Hackle 8-10 a Pheasant Tail for the larger rainbows. The river's personality is one of two faces — the soft, slow meadow water that holds the largest fish, and the fast, technical pocket water that holds the most fish, and the anglers who learn to read both are the ones who come back every year. Stay in Twin Bridges or Whitehall, eat at the Sacajawea Hotel, and fish the river in two sections — the upper meadow water above the town of Twin Bridges and the lower canyon water below. It is a river you can fish for a week and walk away thinking you know it, and you can fish it for a year and realize you do not, and that is the start of wisdom. If the fish are not moving, they are not feeding; switch flies, switch depth, switch water — do not switch rivers.
Spring-fed Jefferson River is flowing at 804 CFS CFS with surface temps near 67°F°F — 6/10 today. Top pick: a Parachute Hopper.
Open 3rd Sat in May — Nov 30
Western District general season
Forecast and on-page guide updated June 22, 2026 (UTC). Open the app for hourly conditions.
Today's Fishing Conditions
Good
Updated 5:09 PM
67°F
804 CFS
1 PM - 3 PM
Parachute Hopper
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June Hatches
Salmonfly
Stonefly
Good salmonfly populations. Fish edges and slower water.
Golden Stone
Stonefly
Extends through summer. Yellow and orange patterns.
PMD
Mayfly
Reliable summer hatch. Morning emergence key.
Mother's Day Caddis
Caddis
Pre-runoff caddis emergence. Good dry fly action.
Caddis
Caddis
Evening caddis activity strong through summer.
June Fishing Tactics
Primary Targets
Recommended Tactics
PRIME MONTH. Salmonfly and stonefly hatches.
Year-Round Fishing Guide
| Month | Water Temp | Tactics |
|---|---|---|
| January | 32-38°F | Deep nymphing, Midges, Streamers |
| February | 33-40°F | Midges, Small nymphs, Deep pools |
| March | 36-45°F | BWO dries, Streamers, Early stonefly nymphs |
| April | 40-50°F | Skwala dries, BWO patterns, Streamers |
| May | 45-55°F | Mother's Day Caddis, Nymphing, Streamers |
| June(Now) | 50-60°F | Salmonfly dries, Golden Stones, PMDs |
| July | 55-68°F | PMDs, Hoppers, Caddis, Attractor dries |
| August | 55-70°F | Hoppers, Tricos, PMDs, Terrestrials |
| September | 48-58°F | BWOs, Streamers, Hoppers |
| October | 40-50°F | Streamers, BWOs, Egg patterns |
| November | 35-42°F | Streamers, Deep nymphs, Egg patterns |
| December | 32-38°F | Deep nymphs, Midges, Slow presentations |
Quick Facts
Brown Trout and Rainbow Trout
freestone
50°F - 60°F
What Makes the Jefferson River Unique?
Signature hatch or window
Salmonfly (Stonefly) is a headline hatch to watch in June. Peak activity often tracks 50–60°F water temps.
Distinctive access
Twin Bridges: Where the Big Hole and Beaverhead meet.
Rules anglers miss
Hoot-owl restrictions may apply in summer.
When is the Best Time to Fish Jefferson River?
Spring
Stoneflies and caddis emerge. Good early season fishing.
Summer
Can run warm - fish early. Watch for hoot-owl closures.
Fall
Browns become aggressive. Excellent conditions.
Winter
Limited but fishable on mild days.
Recommended Equipment for Jefferson River
Rod
9-foot, 5 or 6-weight for most fishing.
Line
Floating line for dries. Sink-tip for streamers.
Leader & Tippet
9-foot tapered leader, 4X-5X tippet.
Waders
Breathable waders. Wade carefully.
Essential Flies
How to Fish Jefferson River: Tips & Tactics
The Jefferson River forms at Twin Bridges where the Big Hole and Beaverhead join. It flows to Three Forks where it becomes part of the Missouri River headwaters.
Best Times of Day
Summer offers good fishing with diverse hatches. The river can run warm in late summer - fish early. Fall brings brown trout into spawning condition.
Recommended Techniques
Float fishing is the most effective method. Match the hatches when active. Streamers produce larger fish. Target structure and deeper water.
Water Conditions
The Jefferson can run warm and low in late summer. Hoot-owl restrictions may apply. Float fishing covers the most water.
Fly Selection
Caddis and stonefly patterns are essential. Hopper patterns in late summer. Streamers for brown trout. BWOs in fall.
Local Knowledge
Twin Bridges is where two famous rivers merge. Watch for hoot-owl restrictions in summer. Three Forks is where Lewis and Clark named the rivers.
Local Tips
Twin Bridges is the confluence of famous rivers. Lewis and Clark passed through here. Three Forks offers historic significance.
Access Points & Parking for Jefferson River
Twin Bridges
Where the Big Hole and Beaverhead meet.
Waterloo
Mid-river access.
Cardwell
Lower river access.
Three Forks
Where Jefferson becomes the Missouri.
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.
Optimal Fishing Conditions
Optimal Flow
800 - 2000 CFS
Best fishing conditions
Optimal Water Temperature
50° - 65°F
Ideal for active trout
Jefferson River Fishing Regulations
Season
Open year-round.
Limits
Check Montana FWP for current regulations.
Special Regulations
Hoot-owl restrictions may apply in summer.
Bait Restrictions
Artificial flies and lures only.
Notes
Watch for low water conditions in summer.
Always verify current regulations with Montana fish and wildlife agency before fishing. Regulations can change annually.
Fly Shops & Guides Near Jefferson River
Local Fly Shops
- Four Rivers Fishing Company - Twin Bridges
- Frontier Anglers - Dillon
- Bozeman Anglers
Guide Services
- Four Rivers Guide Service
- Jefferson River Outfitters
- Montana Trout Guides
Other Rivers You Might Like
Popular forecasts outside Montana—great for trip planning and comparing conditions.
Other Montana Trout Rivers
Bitterroot
Blackfoot
Yellowstone (inside YNP)
Madison
Missouri (below Holter)
Jefferson River — frequently asked questions
When is the best time to fish the Jefferson River?
PRIME MONTH. Salmonfly and stonefly hatches.
What flies should I bring to the Jefferson River?
For the Jefferson River (freestone), carry: Elk Hair Caddis, Hopper, Woolly Bugger, Pat's Rubber Legs, BWO.
What water temperature is best for trout on the Jefferson River?
On the Jefferson River, trout hold between 50° and 65°F. In summer, expect temps to swing with air temperature — fish early.
Do I need a fishing license for the Jefferson River?
Yes — you need a valid Montana fishing license to fish the Jefferson River. Local season: Open year-round.. Daily limit: Check Montana FWP for current regulations..
What hatches should I watch for on the Jefferson River in June?
Salmonfly is the signature hatch on the Jefferson River in June. Match size and adjust leader size to 5X-6X. The fish key in on the emergence during low-light hours, so plan to be on the water at first light.
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