Fly fishing river flowing through a wooded mountain valley

Fly fishing report · West

Tuolumne River below Hetch Hetchy

Tuolumne River below Hetch Hetchy planning with RiverReports flow, official agency sources, NWS weather, access notes, hatch timing, fly picks, and practical safety guidance.

Check flow & weather

Today's fishing decisionSome live data available

Skip today

Verify conditions before committing.

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 supported approachCheck the water first

Watch nextFlow: 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.

Updated Aug 5, 7:23 PM UTCCurrent conditions checked regularly

Before choosing how to fishCheck the water first

There is not enough reliable current information to recommend wading, bank fishing, or floating.

Wade, bank, and floatLimited data

Use the live sources and what you see at the river before choosing an approach.

Check before you drive

Current flow and weather.

Look at whether the river is rising or falling, then check wind, rain, and storms. These can change both safety and fishing.

Before you rely on this report

How current is this report?

Conditions can change quickly. Check these dates before you decide to fish, and open the official source when safety or rules matter.

River conditions: Checked Aug 5, 2026, 3:23 PM
Fishing guidance: Reviewed May 31, 2026
Public access: No reviewed map pin available
Rules and closures: Official rule links checked

View report sources See how reports are verified Report an error

Plan your access

Know where you can enter.

These are public parking, launch, trail, or recreation areas—not secret fishing spots. We never show an angler's private pins, notes, or photos here.

0: Shown on map
3: No map pin

Location checkedDescription only

Area description

Hetch Hetchy area

No map pin

NPS restrictions and entry rules control the first planning decision.

Restrictions and seasonal notes

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.

Official source Checked May 31, 2026

Public land

Downstream Wild and Scenic corridor

No map pin

BLM and forest context helps, but canyon access is demanding.

Restrictions and seasonal notes

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.

Official source Checked May 31, 2026

Area description

Mather / Groveland base

No map pin

Use as a logistics base, not as proof of easy access.

Restrictions and seasonal notes

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.

Official source Checked May 31, 2026

How to fish it

Treat this as a Sierra freestone or canyon-water day.

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.

Use RiverReports for the public chart, then check the listed agency pages because no separate USGS numeric station was verified for this reach.
NPS Hetch Hetchy rules, RiverReports chart, BLM/forest notices, CDFW rules, and weather
NPS Hetch Hetchy rules and BLM Tuolumne Wild and Scenic River context should be checked before assuming any practical access below the dam.
Dam-influenced flow, steep canyon exits, restricted areas, cold water, and remote access

Why the score looks this way

FlowUse caution

HeatUse caution

The NWS forecast is near 84F. Fish early and verify water temperature where trout stress is possible.

SeasonHelps score

Summer: Best dry-dropper and attractor window, especially early and late before canyon heat builds.

Public alertsHelps score

No active NWS alert was returned for this forecast point.

Fishing usefulnessHelps score

Skip during sharp rises, hot low water, unsafe crossings, or road and trail uncertainty.

Read the water

What changes the plan.

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.

Your trip plan

Know when to go—and when to skip it.

Best flows

Stable, clear, cool water with safe crossings and enough depth to hold trout in pockets.

When to skip

Skip during sharp rises, hot low water, unsafe crossings, or road and trail uncertainty.

Local plan

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.

Backup water

Check nearby BlueStreamFly reports if the gauge, rules, or weather do not fit the plan.

Hatches & flies

Bring a flexible box.

TimingWhat to watchUseful flies

SpringLittle stones, BWOs, caddis, and runoff-edge nymph movementStonefly nymph, BWO emerger, hare's ear, caddis pupa

Fly family · report suggests “Stonefly nymph”Stonefly Nymph PatternsStonefly nymph patterns generally emphasize two tails, a broad thorax, segmented abdomen, and bottom contact; rubber legs, biots, beads, and jig hooks define different exact forms.See family guide

Fly family · report suggests “BWO emerger”Blue-Winged Olive PatternsBWO describes a hatch group, not one fly. Nymph, emerger, dry, cripple, and spinner profiles must stay separate because they occupy different parts of the water column.See family guide + 2 more reviewed guides in the Fly Box

Early summerCaddis, PMDs, yellow sallies, and attractor dry-fly windowsElk hair caddis, PMD emerger, yellow stimulator, perdigon

Fly pattern · report suggests “Elk hair caddis”Elk Hair CaddisLook for a tented elk- or deer-hair wing, clipped hair head, dubbed body, rib, and hackle palmered along the body. Compared with the X-Caddis, the Elk Hair Caddis rides higher on its palmered hackle and does not use the X-Caddis's defining trailing shuck and hackleless low-film body. Body color should still be labeled because tiers match different natural caddis colors.See photos & how to fish it

Fly family · report suggests “PMD emerger”Pale Morning Dun PatternsPMD names an insect group, not one fly. Pale nymphs, trailing-shuck emergers, upright or low-riding duns, cripples, and spent-wing spinners stay visibly separate.See family guide + 2 more reviewed guides in the Fly Box

Late summerTerrestrials, ants, beetles, hoppers, and evening caddisFoam ant, beetle, hopper, X-caddis, parachute Adams

Fly family · report suggests “Foam ant”Ant PatternsAnt patterns can be foam, fur-bodied, winged, or sunken. The narrow waist and paired body lobes matter more than one material recipe.See family guide

Fly family · report suggests “beetle”Beetle PatternsBeetle flies range from simple foam shells to hair-bodied and sunken forms. A rounded back and compact profile distinguish the family from ants and hoppers.See family guide + 3 more reviewed guides in the Fly Box

FallBWOs, midges, October caddis, and small streamer windowsBWO emerger, zebra midge, October caddis pupa, olive bugger

Fly pattern · report suggests “zebra midge”Zebra MidgeLook for a very slim tapered thread body, evenly spaced contrasting wire rib, a small bead, and no tail or wing. The reviewed classic is black with silver wire and a silver bead. Red, olive, brown, glass-bead, jig-hook, resin-coated, or tailed forms must remain labeled variations rather than replacing the classic identity.See photos & how to fish it + 2 more reviewed guides in the Fly Box

What to carry

Choose flies for the water you expect.

Use the condition that best matches your plan, then open a reviewed guide to identify and fish the pattern.

ApproachFlies to bringWhen it fits

Dry-dropper fliesStimulator, chubby, elk hair caddis, ant, beetle, pheasant tail, perdigonUse in pocket water, riffles, and summer freestone lanes.

Fly pattern · report suggests “Stimulator”StimulatorLook for a hair tail, dubbed abdomen with palmered hackle, tented hair wing, contrasting front hackle, and bright thorax or head. Colors and sizes vary widely and must remain labeled.See photos & how to fish it

Fly pattern · report suggests “chubby”Chubby ChernobylIdentify the construction, not the color: a long foam overbody over a segmented dubbed underside, rubber legs at two tie-in stations, two distinct buoyant synthetic-yarn wing sections, and a short flash tail. The paired wing stations and layered foam-and-dubbing body separate the reviewed Chubby from the original Chernobyl Ant and from generic foam hoppers or beetles.See photos & how to fish it + 5 more reviewed guides in the Fly Box

NymphsStonefly nymph, hare's ear, caddis pupa, zebra midge, jig nymphUse when cold water, bright sun, or fast seams keep trout down.

Fly pattern · report suggests “hare's ear”Gold-Ribbed Hare's Ear NymphStart with the material architecture, not brown color alone: a short fibrous tail, tapered rough-dubbed abdomen, open metallic rib, fuller buggy thorax, and dark wing case. A bead, flashback panel, hot spot, soft-hackle collar, jig hook, or dry-fly treatment changes the form and must stay named. The two photographed artificials are bead-head variations; the reviewed Fly Fishers International tying guide below is an unweighted Gold-Ribbed Hare's Ear.See photos & how to fish it + 3 more reviewed guides in the Fly Box

StreamersOlive bugger, small sculpin, black leech, sparkle minnowUse near deeper buckets, undercut banks, and slightly colored water.

Fly pattern · report suggests “Olive bugger”Woolly BuggerThe shared pattern language is a marabou tail, chenille or dubbed body, and palmered hackle. Bead heads, dumbbell eyes, flash, rubber tails, colors, and body materials materially change the tied variation and must be labeled. A Woolly Bugger can suggest a leech, crayfish, baitfish, or large nymph, but its marabou-tail and palmered-hackle construction remains a named pattern rather than the separate leech, rabbit-strip Zonker, or shaped-head sculpin families.See photos & how to fish it

Fly family · report suggests “small sculpin”Sculpin PatternsSculpin flies may use muddler heads, cones, dumbbells, jigs, or soft materials. The broad-head, bottom-hugging profile defines the family—not one exact construction.See family guide + 2 more reviewed guides in the Fly Box

Start with a dry-dropper in broken water before adding weight.

Fish near-bank pockets first; canyon trout often hold closer than expected.

Use small streamers in deeper buckets or slightly colored water.

Move often and avoid wasting the best daylight on unsafe crossings.

Rules & closures

Check the official rules before you go.

Open the agency page to confirm the exact river section, species, season, tackle rules, limits, and emergency closures.

Official links checked

Rules for this river or sectionNo special rule found

We did not find a special rule for this river.

We checked the state source but did not find a clearly supported exception for this river. Check the official rules for the exact section you plan to fish.

Rules checkedJul 30, 2026

Report a correction ↗

Always follow the official rule

This summary helps with trip planning. The linked agency rule is the one you must follow.

Updates from anglers

What anglers are seeing.

Recent observations from general areas of Tuolumne River below Hetch Hetchy. We review every update before it appears and never publish exact fishing spots, private access details, or photo locations.

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Angler updates are not loading right now.

You can still use the river plan above. Check back later for recent observations from other anglers.

Where this report comes from

Open the sources we checked.

Fishing guidance checked: May 31, 2026

Site check: Jul 14, 2026. We regularly test report links, live scores, flow and weather data, and page loading. The content date changes only when the fishing guidance or its sources change.

flowRiverReports: Tuolumne River below Hetch Hetchy safetyNWS forecast point near Tuolumne River below Hetch Hetchy regulationCDFW inland fishing information accessYosemite National Park Hetch Hetchy regulationYosemite National Park fishing accessBLM Tuolumne Wild and Scenic River backgroundGenerated regional Tuolumne River below Hetch Hetchy planning image

Common questions

Before you leave.

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.