Karst Spring · Limestone · Castilla y León, ES

Río Ucero

Río Ucero — Cañón del Río Lobos Soria con Ermita de San Bartolomé de Ucero

A short, picturesque Duero tributary rising at the spring of Ucero and falling through the Cañón del Río Lobos before joining the Duero near El Burgo de Osma.

Poor · Brown Trout
Pheasant Tail Nymph · 14-18
Closed season
Out of season. Try elsewhere.
Closed — confidence not applicable today.
What moved it
  • Level0.76 mLast reading 2h ago
  • Water temp6.9°C
  • ClarityClear
Today's fly
Pheasant Tail Nymph
Pheasant Tail Nymph14-18
High-confidence seasonal pick
Conditions on the water
Live gauge
Level
Steady
0.76 m
Last reading 2h ago
Water temp6.9°C
ClarityClear
Weather12°C
WindNE 8 km/h
Pressure1022 hPa
Rain · recent0.0 mm
Rain · ahead10.5 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
Cool — slow
7°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.
Likely species
Gammarids
Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 3 active hatches hour by hour as a supporter.

Start free trial

14-day free trial. Cancel anytime.

Sub-surface · on the nymphunder the surface

Hatch predictions

Supporters see the full sub-surface read.

Start free trial

14-day free trial. Cancel anytime.

Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 2 as a supporter.

Start free trial

14-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
2
2
2
1
Brown SedgeHatch
2
3
3
3
2
Small SpurwingHatch
2
3
3
3
2
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Small Dark OliveHatch
2
3
3
3
2

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.
  • Castilla y León licence required
  • Cañón del Río Lobos natural park — verify access rules and any closed sections before fishing.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Upper Río Duero
35 km
0
Brown trout
Río Revinuesa
43 km
0
Brown trout
Río Abión
43 km
0
Brown trout
Embalse de la Cuerda del Pozo
35 km
Carp · Barbel
Río Arlanza
41 km
Brown trout
Gallery · 2
  1. Río Ucero — Cañón del Río Lobos Soria con Ermita de San Bartolomé de Ucero
    Cañón del Río Lobos Soria con Ermita de San Bartolomé de Ucero
  2. Terrain map of the venue
    Terrain map
About this water

A short, picturesque Duero tributary rising at the spring of Ucero and falling through the Cañón del Río Lobos before joining the Duero near El Burgo de Osma. The Ucero combines karst clarity and a dramatic gorge setting with reliable wild brown trout fishing. The middle reaches between Ucero village and El Burgo offer the most accessible water; the gorge itself is partially within the natural park and requires careful access checks.

  • Limestone
The full read · show the working · for Brown Trout · confidence 75%
How the 0 is built — score × weight = contribution
Temperature48 × 28%13.4
Flow40 × 22%8.8
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity28 × 12%3.4
Conditions total= 57
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
Warmer water — toward the 10–16 °C ideal band — would lift the temperature score.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout Last Sunday of March → 31 July
Related guides
Pyrenees PlaybookSpanish riversEuro Nymphingsubsurface methods
Booking & contacts