Ciénagas are the American Southwest’s most unusual wetlands, yet they are dwindling. This paper addresses what they are, their uniqueness and importance, how they developed, and the causes for the loss of most ciénaga habitat. We also propose a classification system for ciénagas that will contribute to a more meaningful and better-focused discussion about ciénagas, provide an inventory of known ciénagas, and suggest a system of Ciénaga Coordinators with the goal of identifying, restoring, and preserving the few remaining ciénagas. Finally, the inventory from this paper is made available online in an interactive, open, moderated format that will allow anyone to contribute to the correction, evolution, and general improvement and growth of this database, and to download and use the content. A link to this system can be found in a permanent archive of this paper at http://hdl.handle.net/2152/30285.

The data from Appendix B of the paper archived here later prompted formation of the the North American Ciénegas Project (https://www.google.com/fusiontables/DataSource?docid=1n9Z5nJ7BXY0TLBbGjFYzFcRooMWCWK_AQDQVAV24), which hopes to involve a broad community of interested individuals and citizen scientists in further improving and increasing openly shared information about all aridland ciénegas of western North America.