The Río Truful Truful flows through Conguillío National Park in the Araucanía Region of Chile, originating from Laguna Verde and running south to join the Zahuelhue River, forming the Allipén River near Melipeuco. The river drains the eastern slope of the Llaima volcano, and the canyon walls are layered with volcanic ash from past eruptions, creating a striking geological backdrop throughout the run.

There are two recognized paddling sections. The upper section puts in near the border of Conguillío National Park at the base of Llaima volcano. This stretch is continuous class 3 whitewater that maintains its pace throughout, with a few sticky holes around blind bends and sections of overgrown vegetation along the banks. Paddlers should be comfortable with sustained technical water and remain alert. A critical safety consideration on the upper section is the Truful Truful waterfall at the take-out — scouts must identify and exit above this drop before reaching it. The waterfall has been run at certain levels, but the lead-in is described as extremely tricky, and it is generally portaged.

The lower section also sees regular use, with the put-in accessible from the park boundary area. One major rapid on the river, known as the "Trufuliser," is a large feature that most paddlers portage. The overall character of the river is fast and continuous, rewarding paddlers who can read water efficiently and maintain momentum.

The river is located roughly 2 to 3 hours north of Pucón, making it a full-day road trip from that hub. Spring is noted as a period when rivers in this region, including the Truful Truful, run at high levels. The Salto Truful Truful waterfall near Melipeuco is accessible to the general public and is a notable landmark in the area.

The Truful Truful is commonly included in multi-day kayaking itineraries based out of Pucón alongside rivers such as the Fuy, San Pedro, and Blanco. Given the travel time involved, it is typically paddled as a dedicated day trip rather than a casual afternoon run.