For Your Biologists: US Geological Survey Interactive On-Line Biodiversity Map
Link: Biodiversity Information Serving Our Nation (BISON)
Searching for Relict Leopard Frog [an endangered species of frog in the US] gives:
Biodiversity Information Serving Our Nation (BISON) is a product of the U.S. Geological Survey's Core Science Analytics and Synthesis Program. BISON is an information system that allows users to access, explore, and download U.S. species occurrence data from participating data providers.
Clicking on one of the data points shows more detail on the data which can be downloaded in the following formats:
Comma Separated Values (.CSV file)
Google Earth KML file (.KML file)
Zipped Shapefile bundle (.ZIP file)