The Bidasoa forms the Franco-Spanish border, draining western Navarra and the Basque side toward the Atlantic. Navarra-side tributaries and connected border-water sections are mixed limestone-sandstone freestone with moderate spate response. In practical fly-fishing terms this row is about brown trout and some sea-trout influence in lower sections, not about salmon-chasing. Middle-elevation runs with pools and broken water. Access from Bera and the western Navarran valleys.
- Mixed