Tres Islas (Three Islands) is the first of four major rapids in the Wild Mile Section. After the Throne Room the river takes on an unusually exotic appearance. Three large islands divide the river in succession. The First Island splits the river into two flat-water channels, either of which offers a calm, viable route. The Second Island, with its elegant old growth Coihue trees, and glacier crowned peaks in the background, presents one of the most beautiful views on the river. It is also is where the river begins to drop again. The river-right channel is known as Riffle Run and presents no great challenges beyond Class III. The river-left channel is more noteworthy as the river gets compressed between the Second Island and the left river bank. Significant rocks and shallow ledges dominate the river-right shoreline of this channel driving the water to the left. After the first drop the water slows down and comes to a Second Horizon Line; following this drop the water becomes very turbulent at the bottom. Finally a Third Island will appear that divides the river into two flat-water channels before the approach of Roller Coaster rapid.
High and Low Water
The v-tongues become bigger as do the holes behind the rocks. At lower levels there are more pour-overs courtesy of the ledges on river-right. The tongues become steeper but still offer a smooth route.
Boat scout at the top of the river-left channel. At lower water levels, between Entrance and Second Horizon Line, an eddy can be found on river-left if you want a better look at Second Horizon Line. If you opt for the river-right side of the island, Riffle Run can be entirely boat scouted.
The v-tongue of Entrance has a tree reaching out into it from the left shore (since 2001). Be careful of it. The Slot on the right side, in the second drop is harder to see until you are almost right on top of the horizon line.
Floating and bracing through the safe Turbo Zone at the bottom is fun.
Where to Swim
Stay in the flow and try to get to The Slot in the unlikely event of a swim between the horizon lines.
Where to Rescue
Stay at the bottom for any problems someone may have in the turbulence.
Where to Portage
There is a portage trail on river left.
Running the Rapid
The v-tongue of Entrance is on the left and should be approached carefully, to avoid a tree that has been sticking out into the v-tongue. Maneuver to the right side of the v-tongue and follow the main flow of the rapid. Once you have arrived in the calmer area below, move to the right side in preparation for the next horizon line. If you sit up tall, and look over the horizon line, to the bottom of the rapid, you should see where most of the water is flowing out downstream through The Slot – however, you will not be able to see the v-tongue itself. Upon approaching The Slot you will see the v-tongue develop in front of you. Head straight down The Slot into the Turbo Zone, or you can choose to skirt the big waves and turbulence to the right. All options are safe.
Running the Tres Islas river-left channel. Video