RiverReports chart
Recent flow
RiverReports gauge
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All California reports
Tuolumne River below Hetch Hetchy
Generated artwork: BlueStreamFly · Regional illustration; not the exact location.
Should I go fishing?
Check before you go.
Best option: Floating. A float is in play where this report supports boat access and wind, releases, and shuttle logistics are manageable.
Check first: No structured live flow
Fishing rating56
Rating updatedRiver local time:
Why this recommendation?
RiverReports is linked for the flow chart, but this page does not have a structured live flow value the score can read automatically. Treat the rating as conservative and open the chart before committing.
Available live dataMediumHow much of the live flow, weather, and alert data came back.
Confidence in this recommendationLowNo structured live flow
Sources checked often
If you go
- Check first
- Use RiverReports for the public chart, then check the listed agency pages because no separate USGS numeric station was verified for this reach.
- Try
- Start with a dry-dropper in broken water before adding weight.
- Leave when
- Skip during sharp rises, hot low water, unsafe crossings, or road and trail uncertainty.
Flow and weather
Showing server-checked river conditions while current readings refresh.
- Flow
- —
- Live flow is not available here.
- Air forecast
- 63°F
- Next 24h high
- 77.0°F
NWS air forecast near
- Rain chance
- 0%
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 Clear
- Wind
- 5 mph
- Weather checked
More forecast and source details
Mostly Clear
National Weather Service
Tuolumne River below Hetch Hetchy forecast point
The National Weather Service forecast is temporarily unavailable.
Live data
Where these readings come from
RiverReports gauge: Tuolumne River below Hetch Hetchy
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 ↗
- X-CaddisView fly guide ↗
- Parachute AdamsView fly guide ↗
See flies for every season
SeasonWhat to look forFlies to try
Spring
What to look forLittle stones, BWOs, caddis, and runoff-edge nymph movement
Early summer
What to look forCaddis, PMDs, yellow sallies, and attractor dry-fly windows
Late summerThis season
What to look forTerrestrials, ants, beetles, hoppers, and evening caddis
FallThis season
What to look forBWOs, midges, October caddis, and small streamer windows
Each fly name opens its matching Fly Box guide.
More fishing tips
Methods, fish species and trip notes
How to fish Tuolumne River below Hetch Hetchy today.
Best windows come with stable flow, cool water, and access that does not require unsafe crossings. Skip the trip when the gauge rises fast, roads are uncertain, or water is too warm.
Stable release and cool water
Best for careful canyon trout fishing where access is legal.
Changing dam influence
Do not wade if flow or release timing is uncertain.
Restricted access
Treat closures and posted rules as trip-stoppers.
Hot low conditions
Fish early or choose a cooler backup.
Wading, bank fishing or floating?
Best access methodFloating
These scores compare the risks of wading, bank fishing, and floating.
Wading44/100
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.
Floating · Best fit46/100
A float is in play where this report supports boat access and wind, releases, and shuttle logistics are manageable.
Full river report
Is Tuolumne River below Hetch Hetchy worth the trip today? Check flow, weather, hatches, access, and rules for California before you go.
Tuolumne River below Hetch Hetchy should be planned around flow, legal access, and the specific reach you intend to fish. The best plan is built around safe flow, legal access, water temperature, and short realistic reaches instead of trying to cover the whole drainage.
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.
- Attractor fly
- An attractor fly is bright or bold. It draws a strike without copying one exact insect.
- 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
FlowUse caution
RiverReports is linked for the flow chart, but this page does not have a structured live flow value the score can read automatically. Treat the rating as conservative and open the chart before committing.
Best mode nowUse caution
Float: A float is in play where this report supports boat access and wind, releases, and shuttle logistics are manageable.
SeasonHelps
Fall: Cooler nights, lower pressure, and stable water can create the cleanest trout fishing.
WeatherHelps
The current NWS air forecast is about 63F, and the next 24-hour high reaches about 77F. Mostly Clear.
Public alertsHelps
No active NWS alert was returned for this forecast point.
Trip notes
Check these before you choose a reach.
Stable, clear, cool water with safe crossings and enough depth to hold trout in pockets.
Skip during sharp rises, hot low water, unsafe crossings, or road and trail uncertainty.
Hetch Hetchy, Mather, or Groveland is the practical base. Check nps hetch hetchy rules, riverreports chart, blm/forest notices, cdfw rules, and weather, then pick a short legal access plan instead of trying to cover the whole river.
Check nearby BlueStreamFly reports if the gauge, rules, or weather do not fit the plan.
Tuolumne River below Hetch Hetchy 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 current CDFW inland trout rules plus park, forest, or BLM notices before fishing. Rules can vary by reach and season.
Where to access the river
Hetch Hetchy area
NPS restrictions and entry rules control the first planning decision.
Downstream Wild and Scenic area
BLM and forest context helps, but canyon access is demanding.
Mather / Groveland base
Use as a logistics base, not as proof of easy access.
- NPS Hetch Hetchy rules and BLM Tuolumne Wild and Scenic River context should be checked before assuming any practical access below the dam.
- Confirm parking, land ownership, launch status, and current agency notices before relying on any access point.
- Dam-influenced flow, steep canyon exits, restricted areas, cold water, and remote access
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.
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.
How this report was checked
How this report was checked
Reviewed byBlueStreamFly River Review Team
Trip guidance checked
What was checked: This report uses official regulation, flow, weather, access, and public-source material first, then adds practical angler planning guidance without replacing current rules.
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
Is Tuolumne River below Hetch Hetchy usually open for fly fishing?
Check current CDFW rules and land-management notices first. This page gives planning context, but legal status comes from current rules.
Should I wade or float?
Wade-and-move is the baseline. Float only where you have whitewater skill, legal access, and a safe takeout.
Which flow source should I use?
Use the RiverReports chart for a fast read, then verify conditions with the listed park, forest, or water-management sources before fishing.