The Arly comes down off the Aravis fast and cold, gathering snowmelt through spring before slowing enough in its middle reaches to become properly fishable. You want it in late June through July — that short window after the runoff has cleared and before the summer drawdown bites. The fish are wild browns, small but vigorous, in pocket water and short plunge pools that reward a short line and a heavy nymph. Don't come expecting length; this is an intimate river in a big landscape, and the pleasure is in reading the water rather than covering it. The upper valley around Ugine is the postcard country; the lower reaches towards Albertville warm by August and the fishing moves upstream. Bring a 9ft 4-weight for the middle river and a shorter rod for the headwaters.

• Mixed