Freestone · Volcanic · Eastern Sierra

Upper San Joaquin River

The Upper San Joaquin is high-country freestone fishing at its purest — the Middle Fork rising in the wilderness around Thousand Island Lake and running down past Devils Postpile and Reds Meadow in a granite-and-pine canyon below Mammoth.

Species

About as good as it gets

Low and clear — careful approach country. Take your time — read the water before you cast.

75% confidence in this read
Water temperature for brown trout
Ideal
12°C est.ideal 1016°C
0°14°28°
Why this score · for brown trout
  • Temperature10028% weight
  • Flow8022% weight
  • Clarity9518% weight
  • Feeding Time5013% weight
  • Pressure807% weight
  • Insect activity6012% weight
Conditions
Level
Dry recently
No gauge reading
Water temp
11.9°C
Estimated
Clarity
Clear
Air temp
20°C
Wind
SW 16 km/h
Gentle breeze
Pressure
1017 hPa
Rain · 24h
0.0 mm
No rain
Rain · ahead
0.0 mm
No meaningful rain · next 48h

Live readings — water temperature is an estimate where the gauge does not record it.

How to fish it · for brown trout
When
Nymphing can work through most of the day.
Where
Cover mixed depths.
Method
Start with tight-line nymphs and adjust if fish rise or drift higher.
Kit
9 ft #4 rod, floating line, 12 ft tapered leader to 4–5 lb fluoro tippet.
Why this works
Excellent — water temperature is right today, though time of day could be better.
Through the year
0–3 scale · June highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
1
GrannomHatch
2
2
Evening SedgeHatch
2
3
3
3
2
Western Green DrakeHatch
2
2
Flav (Small Western Green Drake)Hatch
2
3
2

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Permits & access
Permit required — see local rules.
  • General-season trout water (~late April–mid-November) but really gated by snowmelt and Reds Meadow road access
  • Verify CDFW rules and wilderness / Devils Postpile National Monument access
  • High-altitude, short season.
Directions
About this water

The Upper San Joaquin is high-country freestone fishing at its purest — the Middle Fork rising in the wilderness around Thousand Island Lake and running down past Devils Postpile and Reds Meadow in a granite-and-pine canyon below Mammoth. The trout are wild rainbows and browns, willing and unsophisticated the way fish that don't see much pressure tend to be, and the fishing is a backcountry pleasure: attractors and dry-droppers in the pocket water, a day spent as much for the place as the catch. It's snowmelt all the way, so the calendar is the snowpack's: roaring and unfishable through the peak melt, then dropping into prime shape through summer and into a quiet, golden autumn. Altitude is the other half of the story — it's cold up here, the season is short, and the road into Reds Meadow only opens when the snow lets it. Time it for the drop after runoff, hike in, and fish a river that still feels like wilderness.

  • Volcanic
Seasons & zones
  • TroutLast Saturday in April → 15 November
Other water nearby · 5