OdonataCentral (http://www.odonatacentral.org/) makes use of relational databases to dynamically generate maps, checklists, and accompanying data. The initial distribution data used on this site is based on the North American Dot Map Project. A project initiated by Nick Donnelly and involving more than 100 contributors from the Odonata community. The goal of this project was to accurately document the distributions of all North American species. Please note, the records contributed by this project represent county centroids, not actual localities. The final product from this project was published as a three volume set in 2004. Donnelly, T.W. 2004. Distribution of North American Odonata. Part I: Aeshnidae, Petaluridae, Gomphidae, Cordulegastridae. Bulletin of American Odonatology 7(4):61-90. Donnelly, T.W. 2004. Distribution of North American Odonata. Part II: Macromiidae, Corduliidae and Libellulidae. Bulletin of American Odonatology 8(1):1-32. Donnelly, T.W. 2004. Distribution of North American Odonata. Part III: Calopterygidae, Lestidae, Coenagrionidae, Protoneuridae, Platystictidae, with data sources and bibliography, parts 1-III. Bulletin of American Odonatology 8(2-3):33-99. More information on this dataset can be found in the Freshwater Metadatabase - BFE_55 (http://www.freshwatermetadata.eu/metadb/bf_mdb_view.php?entryID=BFE_55).