Presa Francisco Zarco

Hardly anyone in La Laguna calls it Francisco Zarco; to locals it is Las Tórtolas. The dam blocks the Nazas River in Lerdo municipality, at the point where the river leaves the mountains through a limestone gorge. It is the lower of the two big reservoirs that water the Comarca Lagunera: upstream sits the much larger Lázaro Cárdenas dam, known as El Palmito, and Las Tórtolas regulates what comes down from it and hands it out for irrigation and the region's water supply. It holds about 380 million cubic metres. In September 2022 it reached 100 percent of its normal level and the water authority opened the gates, sending 100 cubic metres a second down the usually dry bed of the Nazas.

Filling the reservoir drowned the old village of Graceros, whose people moved to Nuevo Graceros, the settlement the dam road now runs through. When the water is low, the tower of the old church sometimes shows above the surface. Past the village the road goes through two rock tunnels to the shore, where there are restaurants, weekend houses and fishing clubs.

The water holds mojarra, largemouth bass, catfish, robaleta and carp. A fishing cooperative has worked the reservoir since the 1980s, and bass tournaments are held here on a catch-and-release basis. The limestone cliffs around the lake are also a sport-climbing area, with some 60 bolted routes on walls such as El Reliz de los Venados, whose east face carries rock paintings that climbers are asked to leave alone.

Below the dam begins Cañón de Fernández State Park, a Ramsar wetland since 2008 covering 17,001 hectares, where the Nazas runs between bald cypresses and more paintings mark the rocks. When the dam releases water, Lerdo's civil protection office patrols the riverside picnic spots and asks people not to swim.