The Nora arrives into the Nalón network from the east, a slate-and quartzite river bringing Cantabrian Mountain character. The upper reaches are step-pool through mixed slate and quartzite; the descent is moderate and the response to rainfall pronounced but not extreme. The middle Nora allows pool-riffle sequences to develop on cobble; these pools are productive and hold fish. The river maintains its spate-responsive character, amber-colored with slate fines, throughout. The wading demands attention in the upper step-pool sections; the middle reaches offer more approachable footing.

Wading: Soft silt at glide margins

In the mountain-to-sea trout rivers of Asturias, olives and other mayflies do much of the work in spring whenever levels and colour allow, followed by strong evening caddis and steady buzzer life through early and mid-summer, with terrestrials and mixed surface food from wooded, pastoral banks rounding out the diet whenever flows drop back into safe wading range.