The Ayasse drops out of Lago Misérin at the head of the Champorcher valley and runs about twenty-four kilometres down to the Dora Baltea near Hône — a proper mountain torrent, clear year-round bar the odd coloured hour after heavy rain, alternating deep pools with long shallow glides. The managed tourist reserve sits above the village, roughly two kilometres of water between the old Brun power-plant intake and the Mellier canal, restocked weekly with rainbow trout and the occasional fish pushing a kilogram. It isn't wild fishing in the way the Dora Baltea's no-kill water is wild fishing — the valley's original wild trout stock reportedly still lingers in the system, by the consortium's own account, but rainbows are what you're actually casting at here — and there's an honesty in that worth having. Bait, spinner or fly all work; nobody minds which you choose.

• Granite schist