The Río Grande de Santiago is one of the longest rivers in Mexico, measuring up long. The river begins at Lake Chapala and continues roughly north-west through the Sierra Madre Occidental, receiving the Verde, Juchipila, Bolaños, and other tributaries. At La Yesca, the La Yesca Dam was completed in 2012 and the El Cajón Dam was completed downstream in 2007. Below El Cajón, the Aguamilpa Dam was completed in 1993, creating a reservoir covering a large part of the territory of the municipality of El Nayar in Nayarit. From Aguamilpa, the river descends to the coastal lowlands, passing by Santiago Ixcuintla and empties into the Pacific Ocean, northwest of San Blas, in Nayarit. The river is viewed by some sources as a continuation of the Lerma River, which flows into Lake Chapala.