The Río Pilmaiquén drains Lago Puyehue and flows northwesterly for approximately 68 kilometers before discharging into the Río Bueno. The river forms part of the boundary between the Los Ríos Region and the Los Lagos Region. The town of Entre Lagos sits near the river's origin, providing convenient logistics for paddlers.

The river is characterized as a high-volume run, and its whitewater is generally rated Class II to III, with wave trains being a notable feature. The volume of water coming out of Lago Puyehue gives the river a big-water character, and paddlers have described it as offering good playboating conditions with glassy play waves. The water is noted as warm relative to other southern Chilean rivers.

A documented kayak route covers 7.5 kilometers beginning at Lago Puyehue near Entre Lagos and ending at Parque La Isla, adjacent to the Salto de la Olla. This stretch passes through a lush, green environment and offers frequent wildlife sightings. Paddlers on this section have reported encountering numerous bird species as well as American mink along the riverbanks.

The easy logistics and proximity to Entre Lagos make day trips straightforward to organize. Water levels influence route selection on the Pilmaiquén and the nearby Río Bueno, and conditions on both rivers are typically evaluated together when planning runs in the area.

The river holds deep cultural significance for the Mapuche communities living along its banks. The Pilmaiquén is considered a sacred waterway, associated with the protective spirit Kintuantü, and is the site of important ceremonial gatherings including the We Tripantü celebration at the winter solstice. Paddlers should be aware that certain areas along the riverbanks are active ceremonial and community sites. One area near the river has also been identified as a protected urban wetland, and landing or disembarking there is not appropriate.