El Cajón Dam, Hydroelectric power station in Nayarit, Mexico

El Cajón Dam, formally Presa Leonardo Rodríguez Alcaine, is a 640 m long and 178 m high rock-fill dam with a concrete face on the Río Grande de Santiago in Santa María del Oro, Nayarit. Its crest carries a road, a white flat-roofed building with blue doors, and smaller cream structures with pale green roofs; a yellow crane stands behind them. The reservoir holds 2,282 hm³.

Construction began in 2003 and was completed in June 2007 at a cost of US$800 million. The dam was formally named Presa Leonardo Rodríguez Alcaine and began operations on 1 March 2007. Its reservoir flooded land in Santa María del Oro, requiring the relocation of 210 inhabitants.

The development of El Cajón Dam brought infrastructure improvements to 40 communities, connecting 20,000 residents through enhanced road networks in the Nayarit region.

The structure is visible from various vantage points along nearby roads and accessible areas. Visitors should be aware that direct access to certain sections may be restricted for safety reasons.

The construction process removed massive quantities of rock using explosives to clear the riverbed. Rather than discarding these large stone fragments, workers incorporated them directly into the dam wall itself.