Freestone · Volcanic · New Mexico, US

San Antonio River / Jemez

San Antonio River / Jemez terrain map

The little waters of the Jemez Mountains — the San Antonio and the upper Jemez above the springs — are about as far from the San Juan's crowds as New Mexico trout fishing gets.

Tomorrow · About as good as it gets
Zebra Midge
Forecast · Tomorrow
About as good as it gets
On the feed top to bottom — start on the rises with a dry, drop a nymph if they stay down.
75% projected
Today's fly
Zebra Midge
Zebra Midge
Conditions on the water · Tomorrow
Live gauge
Level
Steady
0.95 m
Water temp14.6°C
ClarityClear
Weather20°C
WindN 13 km/h
Pressure1018 hPa
Rain · recent0.2 mm
Rain · ahead0.2 mm

The nearest gauge doesn't record temperatures, so we've estimated it — defer to the river keeper's advice.

Water temperature for Brown Trout
Ideal
15°C est.ideal 10–16°C
0°14°28°
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.
Likely species
Mayflies
Caddisflies
Hatch timeline · tomorrowPeak at 11am

12pm(now) — Reed Smut

Stage: On emergersApproach: Emerger or dryActivity: 86%
Also:Mahogany Dun57%
Peak emergence window7 food groups active

Peak activity at 11am — Reed Smut (Reed Smut, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

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Beyond the hatch · worth watchingambient prey(1)

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Evidence
Records-basedModerate confidence

Based on species-occurrence records, not local invertebrate surveys.

Through the year
0–3 scale · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
2
2
2
2
1
Brown DunHatch
2
3
3
3
3
3
3
2
Western Green DrakeHatch
2
2
Flav (Small Western Green Drake)Hatch
2
3
2
Mahogany DunHatch
2
2

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

Ranked for today
Brown Trout fly box
SD
Sex Dungeon
2-6 · Pattern
Proven pattern for this period
Permits & access
Permit required — see local rules.
  • Open all year; verify Special Trout Water reaches and native-cutthroat rules against NMDGF
  • A Habitat Stamp is required to fish USFS/BLM land in New Mexico
  • Some reaches cross pueblo and private land — confirm access
  • THERMAL / MONSOON caution: a small stream that runs thin and warm in high summer and colours quickly in the monsoon.
What's coming
Plan ahead
5-day outlook
Other water nearby · 1
Rio Chama below Abiquiu
56 km
Brown trout · Rainbow trout
About this water

The little waters of the Jemez Mountains — the San Antonio and the upper Jemez above the springs — are about as far from the San Juan's crowds as New Mexico trout fishing gets. This is volcanic country, the streams running cold and clear through meadow and canyon out of the Valles Caldera, holding wild browns and stocked rainbows in water you can read at a glance. Some reaches carry special trout regulations and there's restored native-cutthroat work in the headwater tributaries that deserves a gentle hand. It's classic small-stream fishing: a short dry-dropper, a careful approach, attractors and a small nymph dropped behind. It runs thin and warm by high summer and the monsoon can colour it fast, so early summer once the snowmelt clears and again in autumn are the times to go. A quiet, pretty river that rewards stealth over reach.

  • Volcanic
Water quality · US Clean Water Act
  • Aquatic life: Impaired
What this classification means

EPA ATTAINS assessment unit 'San Antonio Creek (East Fork Jemez to VCNP bnd)' (NM-2106.A_20), 2024 Integrated Report. Aquatic Life use: Not Supporting. Listed impairment causes: Temperature, Metals Other Than Mercury. This is a Clean Water Act assessment-unit classification (the US analogue of WFD), not a live reading.

Status is for the Clean Water Act assessment unit covering this reach.

EPA ATTAINS (Clean Water Act) · NM-2106.A_20

The full read · show the working · for Brown Trout · confidence 75%
How the 81 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time45 × 13%5.9
Pressure80 × 7%5.6
Insect activity59 × 12%7.1
Conditions total= 81
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 1 January → 31 December
Related guides
Euro Nymphingsubsurface methods
Booking & contacts