7-day U.S. Geological Survey chart
Recent flow
Discharge
275 cfs209 cfs
Sep 5Sep 12
Latest reading: 246 cfs. Stable over about 6 hours. Chart covers Sep 5 through Sep 12; readings are provisional and may be revised.
Should I go fishing?
Yes — worth going.
No single best way to fish. Wading and Floating have the same top score. Use current access, footing, weather, and local rules to choose.
Fishing rating94
Rating updatedRiver local time:
Why this recommendation?
USGS shows 246 cfs. The flow has been stable over about 6 hours. USGS marks this reading provisional and may revise it. USGS records for this date (1998-2024, 27 readings) show a typical middle range of 195 cfs to 389 cfs. Flow is within the typical range for this date, so weather, temperature, and access become the next checks.
Available live dataHighHow much of the live flow, weather, and alert data came back.
Confidence in this recommendationHighCurrent flow, weather, alerts, and trip-critical signals support this decision.
Usually checks again about every 45 minutes
If you go
- Check first
- Use USGS Glen flow for this page. RiverReports coverage was not reliable enough to use as the visual source.
- Try
- Read FWP restriction pages before checking fly boxes. The river may not be fishable all day.
- Leave when
- Skip or move on when FWP restrictions are active for your timing, water temperature is unsafe for trout or grayling, flow is too low for an ethical float, or ranch-country access is unclear.
Flow and weather
Showing server-checked river conditions while current readings refresh.
- Flow
- 246 cfs
- Stable over about 6 hoursU.S. Geological Survey may revise this readingWater 54.9°F · 24h high 63.0°F · USGS provisional
- Air forecast
- 38°F
- Next 24h high
- 67.0°F
NWS air forecast near
- Rain chance
- 0%
Latest stored weather check
Partly Sunny
- Wind
- 2 mph
- Weather checked
More forecast and source details
Partly Sunny
National Weather Service
Big Hole River near Glen
The National Weather Service forecast is temporarily unavailable.
Live data
Where these readings come from
Current U.S. Geological Survey gauge: Big Hole River near Glen
Stable over about 6 hoursU.S. Geological Survey may revise this readingObserved
Water 54.9°F · provisional · 24h high 63.0°F provisionalWater observed · high observed
Flies for this time of year
Seasonal starting points, not a live hatch report. Match what you see on the water.
- Blue-Winged Olive PatternsBWOView fly guide ↗
- Sculpin PatternssculpinView fly guide ↗
- Leech PatternsleechView fly guide ↗
See flies for every season
SeasonWhat to look forFlies to try
March to April
What to look forSkwalas, March Browns, BWOs, midges
May to June
What to look forRunoff edge, salmonflies, golden stones, caddis, PMDs
July to August
What to look forHoppers, ants, beetles, nocturnal stones, spruce moths where present
Flies to try
September to OctoberThis season
What to look forMahoganies, BWOs, October caddis, baitfish, fall streamers
Flies to try
Also try mahogany dun, October caddis
Each fly name opens its matching Fly Box guide.
More fishing tips
Methods, fish species and trip notes
How to fish Big Hole River today.
The best Big Hole days have stable post-runoff water, cool temperatures, and no active restriction that changes your plan. If temperatures climb or flows drop, fish early or choose another river.
Runoff edge
Use stonefly nymphs, streamers, and bank tactics only where clarity and safety allow.
Post-runoff stable
Prime dry-dropper, caddis, PMD, and stonefly fishing through riffles and banks.
Low and warm
Check restrictions, fish early if legal, and stop when trout handling is unsafe.
Fall cooling
Use BWOs, mahoganies, October caddis, and streamers in cloud cover.
Wading, bank fishing or floating?
Access choicesNo single best option
Wading and Floating have the same top score. Use current access, footing, weather, and local rules to choose.
Wading94/100
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.
Floating94/100
A float is in play where this report supports boat access and wind, releases, and shuttle logistics are manageable.
Full river report
Is Big Hole River worth the trip today? Check flow, weather, hatches, access, and rules for Montana before you go.
The Big Hole is a premier Montana freestone river, but drought, temperature, runoff, grayling conservation, and float rules can be the first decision. Start with FWP restrictions and the Glen gauge.
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.
- Dry-dropper
- A dry-dropper rig has a floating fly with an underwater fly tied below it.
- 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.
Why this call
Why this score
FlowHelps
USGS shows 246 cfs. The flow has been stable over about 6 hours. USGS marks this reading provisional and may revise it. USGS records for this date (1998-2024, 27 readings) show a typical middle range of 195 cfs to 389 cfs. Flow is within the typical range for this date, so weather, temperature, and access become the next checks.
SeasonHelps
Late summer: Hoppers can be strong, but drought and hoot-owl checks are mandatory.
Water temperatureHelps
USGS water temperature is about 54.9F, and the rolling 24-hour high did not trigger a heat caution. USGS marks the temperature data provisional and may revise it.
Public alertsHelps
No active NWS alert was returned for this forecast point.
Fishing usefulnessHelps
Skip or move on when FWP restrictions are active for your timing, water temperature is unsafe for trout or grayling, flow is too low for an ethical float, or ranch-country access is unclear.
Trip notes
Check these before you choose a reach.
Use USGS 06026210 near Glen for the page's flow trend. Stable post-runoff water is the cleanest window. Low warm water should trigger early fishing only if legal, quick handling, or a move to cooler water.
Skip or move on when FWP restrictions are active for your timing, water temperature is unsafe for trout or grayling, flow is too low for an ethical float, or ranch-country access is unclear.
Start with FWP restrictions and the Glen gauge. Then decide whether the day is a stonefly bank plan, a summer hopper float, an early-morning low-water session, or a fall streamer window.
If the Big Hole is high, low, warm, restricted, or logistically awkward, compare the Bighorn for a steadier tailwater, the Bitterroot for another freestone option, or the Madison for a different Montana trout plan.
Big Hole River 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
Montana FWP rules, current waterbody closures, hoot-owl restrictions, and access-site rules control the Big Hole plan. Check them before fishing.
Where to access the river
Melrose and Maiden Rock area
Common middle-river planning area with FWP access-site checks.
Glen gauge reach
Primary flow reference for this report and a useful middle-river trend.
FWP fishing access sites
Use official FishMT pages for site status, rules, and float logistics.
- FWP access sites and river restrictions should be checked before committing to a float.
- Ranch-country banks are not automatically public access. Use legal sites and respect fences and posted land.
- The river can become too warm or low for ethical trout handling even when a hatch is happening.
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 7 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.
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 Big Hole River report is maintained from USGS Glen flow data, Montana FWP fishing regulations, current closure and restriction sources, Big Hole drought-management information, FishMT waterbody and access records, weather, media-credit, and freestone trout planning sources.
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 first before fishing the Big Hole River?
Check Montana FWP restrictions, Glen flow, water temperature, access-site status, and weather before fishing.
Are there special fishing rules on the Big Hole River?
Yes. Montana rules plus current restrictions or hoot-owl closures can change the day.
Is the Big Hole River a good fly-fishing river?
Yes, if you match the reach, season, target species, water temperature, and current access rules. This report is built to help you choose that plan.
What flies should I bring for the Big Hole River?
Bring the hatch-chart flies, confidence nymphs, and a backup streamer or warmwater box so you can adjust to flow, clarity, and temperature.
How should I plan access for the Big Hole River?
Use FWP fishing access sites and legal float/wade access. Ranch banks and informal pullouts are not automatically public.