Main western Pyrenean Ebro tributary crossing Aragón into Navarra. Key trout reaches sit around Yesa and the pre-Pyrenean corridor, where bigger-water nymphing and caddis-driven dry-fly windows define the main trout interest.
- Mixed
Rules at a glance
- Public water
- Licence required
Water temperature for Brown Trout
Ideal16°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the Navarrese trout season. Spring olives April through May; sedges through summer; small dark flies into the autumn close.
Where
Pool tails and the seams behind boulders through the upper Aragón valley. Pyrenean piedmont character — clear water, classic Iberian wild brown trout water.
Method
Upstream dry to risers; dry-dropper through the riffles. The Aragón runs clear Pyrenean water — long leader, fine tippet.
Kit
9 ft #4 — French freestone default. Floating line, 12 ft leader to 4 to 5 lb fluoro. Studded boots.
Why this works
Water at 19.8°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Hatch timeline · todayPeak at 5pm
12pm(now) — Daddy Long Legs
Stage: On emergersApproach: Emerger or dryActivity: 21%
Peak activity at 5pm — Pale Evening (Pale Evening, 7 food groups active)
Sub-surface · on the nymphunder the surface
Hatch predictions
Supporters see the full sub-surface read.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalHigh confidence
Backed by regional invertebrate surveys; no sampling on this exact reach yet.
Through the year
0–3 scale · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
1
Evening SedgeHatch
2
3
3
3
2
Alpine RhithrogenaHatch
1
2
2
1
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
2
2
2
2
1
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Brown Trout fly box
Permits & access
Permit required — see local rules.
- Gobierno de Navarra fishing licence required
- Yesa reservoir regulates flow downstream, and the exact tramo and permit structure should be checked in the current official Navarra calendar before travel.
What's coming
Plan ahead
5-day outlook
Water here around 20°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
Terrain map
About this water
The full read · show the working · for Brown Trout · confidence 80%
How the 0 is built — score × weight = contribution
Temperature14 × 28%3.9
Flow80 × 22%17.6
Clarity40 × 18%7.2
Feeding Time40 × 13%5.2
Pressure80 × 7%5.6
Insect activity36 × 12%4.3
Limiting factor: Water temperature (19.8°C) is outside Brown Trout's preferred range (10–16°C)= 44
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
Cooler water — back toward the 10–16 °C ideal band — would lift the score and ease welfare.
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout 1 May → 30 June
The Aragón straddles Navarra and Aragón communities. Upper sections (Jaca area) may follow Aragonese regulations. Navarran sections fall under RSS rules — all catch-and-release, daily basin permit required. Below Yesa reservoir the river changes character: regulated tailwater flow. Check tramo-specific status for the exact stretch.
Related guides
Booking & contacts
Río Aragón
Main western Pyrenean Ebro tributary crossing Aragón into Navarra.
Water temperature for Brown Trout
Ideal16°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the Navarrese trout season. Spring olives April through May; sedges through summer; small dark flies into the autumn close.
Where
Pool tails and the seams behind boulders through the upper Aragón valley. Pyrenean piedmont character — clear water, classic Iberian wild brown trout water.
Method
Upstream dry to risers; dry-dropper through the riffles. The Aragón runs clear Pyrenean water — long leader, fine tippet.
Kit
9 ft #4 — French freestone default. Floating line, 12 ft leader to 4 to 5 lb fluoro. Studded boots.
Why this works
Water at 19.8°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Hatch timeline · todayPeak at 5pm
12pm(now) — Daddy Long Legs
Stage: On emergersApproach: Emerger or dryActivity: 21%
Peak activity at 5pm — Pale Evening (Pale Evening, 7 food groups active)
Sub-surface · on the nymphunder the surface
Hatch predictions
Supporters see the full sub-surface read.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalHigh confidence
Backed by regional invertebrate surveys; no sampling on this exact reach yet.
Through the year
0–3 scale · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
1
Evening SedgeHatch
2
3
3
3
2
Alpine RhithrogenaHatch
1
2
2
1
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
2
2
2
2
1
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Brown Trout fly box
Permits & access
Permit required — see local rules.
- Gobierno de Navarra fishing licence required
- Yesa reservoir regulates flow downstream, and the exact tramo and permit structure should be checked in the current official Navarra calendar before travel.
What's coming
Plan ahead
5-day outlook
Water here around 20°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
Terrain map
About this water
Main western Pyrenean Ebro tributary crossing Aragón into Navarra. Key trout reaches sit around Yesa and the pre-Pyrenean corridor, where bigger-water nymphing and caddis-driven dry-fly windows define the main trout interest.
- Mixed
The full read · show the working · for Brown Trout · confidence 80%
How the 0 is built — score × weight = contribution
Temperature14 × 28%3.9
Flow80 × 22%17.6
Clarity40 × 18%7.2
Feeding Time40 × 13%5.2
Pressure80 × 7%5.6
Insect activity36 × 12%4.3
Limiting factor: Water temperature (19.8°C) is outside Brown Trout's preferred range (10–16°C)= 44
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
Cooler water — back toward the 10–16 °C ideal band — would lift the score and ease welfare.
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout 1 May → 30 June
The Aragón straddles Navarra and Aragón communities. Upper sections (Jaca area) may follow Aragonese regulations. Navarran sections fall under RSS rules — all catch-and-release, daily basin permit required. Below Yesa reservoir the river changes character: regulated tailwater flow. Check tramo-specific status for the exact stretch.
Related guides
Booking & contacts