Where the Chimehuín and Aluminé join forces, the Collón Curá turns into a broader, slower river running through open volcanic steppe — bigger water with more room to swing a streamer and less need for the pinpoint presentation its tributaries demand. The current warms and colours slightly as it crosses lower ground, favouring browns willing to hold in deeper runs and undercut banks rather than sipping naturals off the surface. Dry-dropper rigs still take fish, but a Woolly Bugger or Muddler Minnow worked through the softer water often draws the better takes. Regulation requires single barbless hooks and mandatory catch-and-release for salmonids along the river, alongside a modest perca harvest allowance. A guide who knows the run order between access points pays for itself — the water looks uniform from the bank but fishes in distinct beats.

• Volcanic