Black Hills Institute of Geological Research, located in Hill City, S.D., has been one of the leaders in paleontological excavations and preparation since 1974. It s primary task is to collect, preserve and provide well-prepared fossil specimens, minerals, cast replicas and related information to museums, researchers and private collectors. For more than 25 years, BHI has been developing one of the most comprehensive paleontological and mineralogical collections from its region, collateral collections from other regions and an extensive reference library. This library covers a large portion of the vertebrate and invertebrate paleontology from the North American western interior, along with the geology and mineralogy of this region. BHI also carries a large selection of fossil mammals from a range of regions and geological eras including the Oligocene, White River Group, fish from the Eocene, Green River Formation and the Cretaceous of Lebanon.