The upper Segre above La Seu d'Urgell is a limestone river rising in high Pyrenees near Andorra and flowing southeast through mountain valleys and gorges. Clear, alkaline freestone holds excellent wild brown trout with high biodiversity. Technical runs alternate with pocket water and pools throughout. The Segre's upper reaches — Organyà, Montferrer, La Seu d'Urgell zones — are the true trout destination. Good dry-fly and nymphing opportunities throughout.
- Limestone