Over the last decade, evidence has accumulated that water level declines in Cuatrociénegas, the world’s most biodiverse spring-based wetland and an important Mexican desert biodiversity hotspot and protected area, are related to largescale groundwater-based agriculture in adjoining valleys that contribute to the aquifer that feeds its springs and wetlands. At the same time, the area has transformed into a popular tourism destination, with rapid and massive expansion of the hotel industry and visitation. However, two of the primary developers established non-profit foundations with conservation- and community-support objectives, and are working together with the Federal Reserve System (CONANP), local conservation groups, regional universities, and the municipal government to assure that development is sustainable and compatible with biodiversity conservation. Much remains unknown about basic ecology and genetics of its highly endemic and diverse fish fauna, its three endemic turtles (not to mention many other endemic herps, invertebrates and plants) and there are new initiatives working to support field and laboratory research, as well as establishment of captive breeding programs. Hydrogeology/karst aquifer expertise is obviously also important. I hope that this talk, including review of DFC's off and on involvement in Cuatrociénegas since the 1960's, will spark new players to help continue the long legacy of DFC's focus on sustainability of both Ash Meadows and Cuatrociénegas, thus broadening and strengthening the diverse collaborations required to save this now critically-endangerd ecosystem, just like DFC did for Ash Meadows long ago.