Estero Los Pejerreyes is a water body in Chile's Santiago Metropolitan Region. It is a tributary of the larger Estero Casablanca, which is a 40-kilometer-long river system. The waterway is featured on digital mapping and fishing platforms, which indicates it is recognized for recreational use. These platforms offer tools for viewing access points and planning trips, suggesting there are established locations for entering and exiting the water. The surrounding region is part of the Región Metropolitana de Santiago, which typically features a landscape influenced by the central Chilean topography. As a tributary within a larger river network, its flow and character are connected to the Estero Casablanca system. Paddlers should consult local resources for current access, conditions, and any regulations, as the general information available does not specify seasonal water patterns, water quality, specific hazards, or on-site facilities for boaters.