Lamar River
Lamar Valley · Yellowstone NP
NW Wyoming, USA
Open live forecast →Target species: Cutthroat.
Stream gauge: 06188000. Flow and water temperature update on every refresh.
About this Water
- Freestone
- Best months: July–Sept (river opens after runoff)
The Lamar Valley in northeastern Yellowstone National Park is the heart of the park's wildlife viewing and trout fishing experience — the Lamar River and its tributaries (Slough Creek, Soda Butte) hold native Yellowstone cutthroat trout in classic meadow-stream character through bison-and-wolf country. The Lamar mainstream is broad, slow, and demands patient meadow-stream fishing. Slough Creek is more famous: a series of meadow stretches separated by short pocket-water reaches, holding fish that have seen every fly. Cutthroat-only regulations apply throughout.
The Lamar Valley is the most-photographed wildlife viewing area in Yellowstone — anglers fishing the river share the meadow with bison herds, wolves, grizzly bears, and the occasional pronghorn, an experience genuinely unique among American trout fisheries.
January Outlook
The Lamar River inside Yellowstone National Park is closed during the winter/spring period. The Lamar Valley is one of North America's premier wildlife destinations in winter — wolves, bison, and elk are abundant in the valley.
Productive Patterns
- Closed — YNP winter closure
Tips
The Lamar Valley in January is prime wolf watching territory. Visit with a spotting scope and join the wolf observer groups near the Confluence. The fishing season is months away.
Water Notes
River closed. Valley accessible via snowcoach or personal snowmobile permit. Deep snow conditions.
February Outlook
Still closed. The Lamar Valley's winter wildlife spectacle continues. The Northeast Entrance road may be closed. Check YNP winter access conditions.
Productive Patterns
- Closed — YNP winter closure
Tips
February is peak wolf-watching season in the Lamar. The fishing opens in late spring — check YNP regulations for current season start dates.
Water Notes
Closed. Winter wildlife season at peak.
March Outlook
The Lamar drainage remains closed under YNP spring regulations. The season typically opens in late May or early June. The Northeast Entrance road (Cooke City) reopens in mid-May in most years.
Productive Patterns
- Closed — YNP spring closure
Tips
The Northeast Entrance to Yellowstone is typically the last road to open — check dates at nps.gov/yell. The Lamar opens with the spring park season.
Water Notes
Closed through late May–June depending on conditions and regulations. Northeast Entrance road closed.
April Outlook
Still closed under YNP regulations. The Northeast Entrance road is still closed and the Lamar drainage is inaccessible. Late April sometimes sees early season opener in the northern range.
Productive Patterns
- Closed — YNP regulations
Tips
Check nps.gov/yell for current opening dates. The Lamar Valley begins its spring transformation in April with early wildflowers and wildlife.
Water Notes
Closed. Northeast Entrance road opens mid-May in most years.
May Outlook
The Northeast Entrance to Yellowstone typically opens in mid-May giving access to the Lamar drainage. The season may open in late May depending on current YNP regulations. The valley is spectacular in early spring.
Productive Patterns
- Pre-season or just opening
Tips
Check nps.gov/yell for the current Northeast Entrance opening date and fishing season start. The Lamar opens with outstanding early-season cutthroat and Yellowstone cutthroat fishing.
Water Notes
Accessible mid-to-late May. Season opening variable. Check current regulations.
June Outlook
The Lamar in Yellowstone NP opens in late May to fly fishing. Cutthroat trout are cooperative and the wildlife watching is world-class.
Productive Patterns
- Elk Hair Caddis
- Stimulator
- PMD
- Beadhead Nymph
Tips
The Lamar Valley section is more accessible than the canyon. Fish the slower sections for rising cutthroat. Wildlife corridors mean bears and wolves are common — be alert.
Water Notes
High flows from snowmelt 600–2,000 cfs. Drops to fishable by late June. Clear and cold 48–58°F.
July Outlook
Prime season. Cutthroat trout feed freely on caddis and PMDs. The Lamar Valley is Yellowstone's signature wildlife corridor.
Productive Patterns
- Elk Hair Caddis
- PMD
- Hopper-Dropper
- Stimulator
Tips
Wade the meadow sections with wildlife watching between hatches. The cutthroats are relatively eager by Yellowstone standards. Hopper-dropper in the afternoon.
Water Notes
400–900 cfs. Water 56–64°F. Prime summer fishing conditions.
August Outlook
Hopper season in the Lamar Valley with spectacular wildlife viewing. The experience of fishing here alongside bison, wolves, and bears is truly unique.
Productive Patterns
- Hopper
- Chubby Chernobyl
- Elk Hair Caddis
- Stimulator
Tips
The Lamar's broad meadow channels are ideal hopper water. The confluence with Soda Butte Creek is particularly productive. Always pack bear spray.
Water Notes
300–600 cfs. Water 58–65°F. Best conditions of the year for Lamar Valley fishing.
September Outlook
Excellent fall fishing with fewer tourists. The cutthroats are in prime condition and BWO hatches begin.
Productive Patterns
- Blue Winged Olive
- Hopper
- Elk Hair Caddis
- Nymph
Tips
September in the Lamar Valley is outstanding — wolves and elk herds are active and the fishing is excellent. The cutthroats stack in the deeper runs before winter.
Water Notes
250–500 cfs. Cooling 50–58°F. Excellent fall conditions in one of the world's great wildlife corridors.
October Outlook
The Lamar Valley in October offers excellent fishing and spectacular wildlife viewing. Bull elk are bugling and wolves are active in the valley. Brown trout begin pre-spawn movement. A top-tier October fishing destination.
Productive Patterns
- Streamer
- Blue Winged Olive
- Egg
- Large Attractor
Tips
October in the Lamar combines world-class fishing with the peak of the elk rut and active wolf packs. The Northeast Entrance road typically stays open until the first significant snowfall. An unforgettable experience.
Water Notes
100–350 cfs. Cold 42–52°F. Clear and beautiful. Season typically closes early November.
November Outlook
The Lamar Valley season closes in early November as Yellowstone transitions to winter access. The final fishing days in the valley are extraordinary as the first snow falls.
Productive Patterns
- Season closing by early November
Tips
Check current YNP season closing dates. The Northeast Entrance closes when snow makes it impassable. The final days of October and early November are among the most memorable in the park.
Water Notes
Season closing. Cold and approaching first snow. Access dependent on weather and road conditions.
December Outlook
Yellowstone's Lamar Valley is closed for the winter fishing season. Accessible only via snowcoach or snowmobile permit. The valley's winter wildlife spectacle is beginning.
Productive Patterns
- Closed — winter season
Tips
The Lamar's winter wildlife season begins. Contact Yellowstone Forever or park concessions for snowcoach tours. The fishing season is months away.
Water Notes
Closed. Winter access via snowcoach or permit only.
Hatch Calendar
| Insect | Peak | Active | Size | Productive Patterns |
|---|---|---|---|---|
| Blue Winged Olive Baetis spp. |
May, Sep | Apr, May, Jun, Sep, Oct | #18–22 |
|
| Caddis (Brown/Tan) Hydropsyche spp. |
Jun, Jul | Jun, Jul, Aug | #14–18 |
|
| Pale Morning Dun Ephemerella infrequens |
Jun, Jul | Jun, Jul, Aug | #16–18 |
|
Access & Approach
Cooke City and Mammoth, MT are the main bases. National park entry fee + Yellowstone fishing license required. Catch-and-release / barbless single-hook regulations.
Nearby Fly Shops
- Big Sky Anglers
- Parks' Fly Shop
- Blue Ribbon Flies
- Madison River Outfitters
- Big Sky Anglers
Regulations & License
Fishing in Wyoming requires a current license. Always verify season dates, bag limits, and any special-regulation waters before you fish.
Wyoming fishing regulations & license →
Nearby Waters
Closest Waters
More in This Region
About Current
Lamar River conditions on Current combine real-time flow data (USGS, WSC, CDEC, CEHQ), weather, tide predictions, hatch probabilities calibrated to this specific water, and recent fly shop reports from the area.
Lamar River is one of 245 hand-curated waters in Current. The app and web forecast also generate AI outlooks for any unlisted river, lake, or saltwater flat anywhere in the world — drop a pin or paste a name and Current produces a fresh seasonal outlook with weather, flow context, and recommended techniques.
Open the live forecast for today's numbers and the 7-day outlook, or download the iOS app to carry it with you on the water.