7-day U.S. Geological Survey chart
Recent flow
Discharge
1,020 cfs876 cfs
Sep 4Sep 11
Latest reading: 876 cfs. Falling over about 6 hours. Chart covers Sep 4 through Sep 11; readings are provisional and may be revised.
All Wyoming reports
Yellowstone River In Yellowstone Park
Photo: Brocken Inaglory Opens in a new tab. · CC BY-SA 3.0
Should I go fishing?
Check the water temperature first.
Water temperature is unconfirmed. Use a stream thermometer; stop trout fishing at 70°F or warmer, or sooner if fish show stress.
Fishing rating74
Rating updatedRiver local time:
Why this recommendation?
USGS shows 876 cfs. The flow has been stable over about 6 hours. USGS marks this reading provisional and may revise it. USGS records for this date (1927-2025, 96 readings) show a median near 1,180 cfs and the lower quartile near 957 cfs; today's flow is below normal for the date. This is below normal, so edge depth, temperature, and pressure matter.
Available live dataHighHow much of the live flow, weather, and alert data came back.
Confidence in this recommendationMediumWater temperature not verified; do not use this score to clear warm-water risk.
Usually checks again about every 45 minutes
If you go
- Check first
- Check the 2026 NPS rule PDF and the Southeast/Northeast reach pages before fishing.
- Try
- Confirm the exact open reach before leaving the vehicle.
- Leave when
- Skip the Yellowstone inside the park when the exact reach is closed, native trout rules are unclear, road or wildlife conditions are poor, the river is high or cold after runoff, or the day depends on downstream Montana assumptions.
Flow and weather
Showing server-checked river conditions while current readings refresh.
- Flow
- 876 cfs
- Falling over about 6 hoursU.S. Geological Survey may revise this reading
- Air forecast
- 51°F
- Next 24h high
- 66.0°F
NWS air forecast near
- Rain chance
- 2%
This is an air forecast, not a river-temperature reading. Check the water with a stream thermometer before fishing in hot weather.
Latest stored weather check
Mostly Cloudy
- Wind
- 5 mph
- Weather checked
More forecast and source details
Mostly Cloudy
National Weather Service
Yellowstone River at Yellowstone Lake Outlet
The National Weather Service forecast is temporarily unavailable.
Live data
Where these readings come from
Current U.S. Geological Survey gauge: Yellowstone River at Yellowstone Lake Outlet
Falling over about 6 hoursU.S. Geological Survey may revise this readingObserved
Flies for this time of year
Seasonal starting points, not a live hatch report. Match what you see on the water.
- Ant PatternsFoam antView fly guide ↗
- Beetle PatternsbeetleView fly guide ↗
- Grasshopper PatternshopperView fly guide ↗
- Caddis Patterns by Stagesmall caddisView fly guide ↗
- Parachute AdamsView fly guide ↗
See flies for every season
SeasonWhat to look forFlies to try
Late May to June
What to look forCold-water midges, BWOs, caddis, and early stoneflies when park water is open
July
What to look forPMDs, caddis, golden stones, Green Drakes in suitable water, and spinner falls
Flies to try
August to SeptemberThis season
What to look forTerrestrials, ants, beetles, hoppers, small caddis, and evening spinners
October
What to look forBWOs, midges, streamers where legal, and short cold-weather feeding windows
Each fly name opens its matching Fly Box guide.
More fishing tips
Methods, fish species and trip notes
How to fish Yellowstone River In Yellowstone Park today.
Fish only after confirming the exact reach is open and accessible. Stable weather, clear water, and legal native-trout reaches are the right combination. Uncertain closures are a hard stop.
Open, clear, cool reach
Best for dries, dry-droppers, and careful sight fishing.
Closed or uncertain reach
Do not fish. Move to a confirmed legal water instead.
High spring water
Even if open, crossing and wading can be dangerous. Use edges only.
Warm summer water
Fish early, check temperature, and reduce native-trout handling stress.
Wading, bank fishing or floating?
Best access methodWading
These scores compare the risks of wading, bank fishing, and floating.
Wading · Best fit74/100
Wading is in play only where your chosen access has clear footing, legal entry, and no forced crossings.
Bank fishingNot recommended
This report does not recommend bank fishing on this reach.
FloatingNot recommended
This report does not recommend floating this reach.
Full river report
Is Yellowstone River In Yellowstone Park worth the trip today? Check flow, weather, hatches, access, and rules for Wyoming before you go.
The Yellowstone River inside the park crosses different management zones and several permanent closures. The page is useful only when it keeps the exact reach, open dates, native cutthroat rules, and road status in front of fly choice.
Fishing words used on this page
- U.S. Geological Survey (USGS) gauge
- A USGS gauge is an official river station that measures flow or water height.
- Cubic feet per second (cfs)
- Cubic feet per second, or cfs, shows how much water passes the gauge each second.
- Nymph
- A nymph is a young water insect. Anglers also use the word for a fly that copies it.
- Riffle
- A riffle is shallow, fast water broken by rocks.
- Blue-winged olive (BWO)
- Blue-winged olives, or BWOs, are small mayflies that often hatch in cool or cloudy weather.
- Caddis
- Caddis are small water insects. The adults look a little like tiny moths.
- Emerger
- An emerger copies an insect as it rises from below the water toward the surface.
- Midge
- Midges are tiny flies and a common trout food, especially in cold water.
- Pale morning dun (PMD)
- Pale morning duns, or PMDs, are light-colored mayflies that often hatch in warmer months.
- River reach
- A reach is one named section of a river or stream.
Why this call
Why this score
FlowUse caution
USGS shows 876 cfs. The flow has been stable over about 6 hours. USGS marks this reading provisional and may revise it. USGS records for this date (1927-2025, 96 readings) show a median near 1,180 cfs and the lower quartile near 957 cfs; today's flow is below normal for the date. This is below normal, so edge depth, temperature, and pressure matter.
SeasonHelps
Fall: Cooler water and fewer crowds can help, but road/weather changes matter.
WeatherHelps
The current NWS air forecast is about 51F, and the next 24-hour high reaches about 66F. Mostly Cloudy.
Public alertsHelps
No active NWS alert was returned for this forecast point.
Fishing usefulnessHelps
Skip the Yellowstone inside the park when the exact reach is closed, native trout rules are unclear, road or wildlife conditions are poor, the river is high or cold after runoff, or the day depends on downstream Montana assumptions.
Trip notes
Check these before you choose a reach.
Use USGS 06186500 at the Yellowstone Lake Outlet for upper-river context. Stable or gradually improving flows are easiest to plan around, while high runoff, canyon closures, road impacts, or cutthroat conservation concerns should end the trip plan.
Skip the Yellowstone inside the park when the exact reach is closed, native trout rules are unclear, road or wildlife conditions are poor, the river is high or cold after runoff, or the day depends on downstream Montana assumptions.
Start with the NPS fishing page and 2026 rule PDF, then match the day to the Southeast or Northeast reach guidance. Use the lake-outlet gauge for upper context, and keep canyon, Hayden Valley, Fishing Bridge, and other closure notes in front of fly choice.
If the Yellowstone reach you wanted is closed, high, crowded, or unsafe, compare the Madison inside the park, the Montana Yellowstone downstream of the park, or the Snake River for a different cutthroat plan.
Yellowstone River In Yellowstone Park access and rules.
Use these places as starting points. Open the access link below and check posted signs before you park or enter.
Before you go
Check Yellowstone National Park's current rule PDF and section-by-section NPS pages before fishing. This report does not replace the park permit, open dates, permanent closures, or native-fish conservation rules.
Where to access the river
Yellowstone Lake outlet context
Use the USGS lake-outlet gauge, then confirm NPS open-water rules.
Southeast Yellowstone reach checks
NPS Southeast rules include open dates and important permanent closures.
Northeast Yellowstone reach checks
NPS Northeast rules include different native/nonnative fish handling details.
- Fishing Bridge, LeHardys Rapids, Hayden Valley, canyon, and other reach closures must be checked in current NPS rules.
- Downstream of Gardiner is a Montana rule topic, not this park page.
- Road, bear, bison, fire, and weather conditions can change access after the page is reviewed.
Sources and report details
Official agencies and primary river operators come first. Secondary tools are labeled so you know what carries the most weight.
Rules and closures
Check what is allowed, where the rule applies, and whether the river is open.
Flow and weather
Check the latest river reading and forecast before you leave.
Access and land
Check public entry points, land rules, and seasonal access changes.
More helpful links
Use these links for stocking, safety, and other local details.
See all 9 checked sources
Rules and closures
Check what is allowed, where the rule applies, and whether the river is open.
What this source covers
Open the current rules and check the river section, season, and special limits.
What this source covers
Open the current rules and check the river section, season, and special limits.
What this source covers
Open the current rules and check the river section, season, and special limits.
What this source covers
Open the current rules and check the river section, season, and special limits.
Flow and weather
Check the latest river reading and forecast before you leave.
What this source covers
Open this page and check the latest safety advice before your trip.
What this source covers
Open this river reading to check the latest level, flow, and update time.
Access and land
Check public entry points, land rules, and seasonal access changes.
What this source covers
Open the land or access page, then check signs before you park or enter.
More helpful links
Use these links for stocking, safety, and other local details.
What this source covers
Open this page for more river information and check when it was last updated.
What this source covers
Open this page and check the latest safety advice before your trip.
How this report was checked
How this report was checked
Reviewed byBlueStreamFly River Review Team
Trip guidance checked
What was checked: This report is maintained from current regulation, access, flow, weather, and public planning sources so anglers can make better trip decisions than a raw gauge or generic overview would allow.
Live measurements and forecasts keep their provider timestamps. Rules, access, and trip guidance use the source-review date shown here. BlueStreamFly planning advice is editorial interpretation, not an agency notice.
First-hand experience: BlueStreamFly does not claim a first-hand visit or local field test for this report unless a real contributor is explicitly named and linked.
Quick questions
What should I check before fishing Yellowstone River In Yellowstone Park?
Yellowstone permit, 2026 NPS reach rules, permanent closures, road status, USGS flow, and weather
Which flow should I use for Yellowstone River In Yellowstone Park?
Use USGS 06186500 at the Yellowstone Lake outlet for upper park context, then check current NPS reach rules and conditions before treating flow as fishable access.
Where should I start on Yellowstone River In Yellowstone Park?
Start by choosing the exact park reach, then compare it against the NPS rule PDF, Southeast/Northeast pages, current conditions, and road status.
Can I wade Yellowstone River In Yellowstone Park?
Only in confirmed open reaches and safe flows. Closed zones, canyon water, wildlife, and cold current make casual wading a bad default.