NatureServe Network Species Occurrence Data
This dataset consists of "Element Occurrence" (EO) records for rare and endangered species of the United States and Canada that are managed by NatureServe's network of natural heritage programs and conservation data centers. Occurrences are documented by voucher specimens and other forms of ecological observations, and include spatially explicit data on the location and extent of populations, together with data on abundance and population condition. Due to the potential sensitivity of endangered species locations, only non-sensitive geographic data are provided in this dataset. Species-specific criteria used to define element occurrences, as well as standards for documenting and mapping element occurrences are available on the NatureServe web site at: http://www.natureserve.org/prodServices/heritagemethodology.jsp.