Small enough that you can step across it in places, which shouldn't encourage false confidence. The Riosa holds wild browns in runs no wider than a doorway, under alders that make the casting interesting. The fish are modest in size and precise in their requirements, and they will let you know immediately if you've been sloppy.
The Riosa arrives into the Nalón system bringing steep Cantabrian descent and mixed lithology character. The upper reaches are step-pool slate and quartzite; the descent is steep and response to rainfall pronounced. The middle Riosa allows pool-riffle sequences to develop on cobble; these pools are known and respected. The river maintains its responsive character — quick to rise, quick to fall, connected fully to mountain weather — throughout.
Wading: Wet boulder tops and lichen glazed bedrock steps
- Mixed
- Confined
- Step pool
- Pocket water