History of Research in the Uinta Basin

O.C. Marsh led the first paleontological expedition to the Uinta Basin in 1870 as part of a Yale College Scientific Expedition. In an unexplored area between the Green and White Rivers, Marsh’s party collected numerous fossil mammals, the beginnings of an assemblage that would later define the Uintan NALMA, a time period that spans approximately 46.5 to 40 Ma. In the 1880s, Francis Speir of Princeton University collected in this same area and the mammalian fossils he collected were studied by W. B. Scott and H.F. Osborn, whose efforts produced the first comprehensive publications on mammals from the Uinta Formation. At the turn of the century, the Carnegie Museum sent expeditions to the Uinta Basin at different times led by O.A. Peterson and then Earl Douglass. Peterson initially described many of the medium and smaller-sized mammals from the Uinta Formation, many now recognized as index taxa for the Uintan NALMA and therefore crucial for understanding Uintan biochronology on both the regional and continental scales. After these initial expeditions, museums across North America sent parties to collect small samples of Uintan mammals, the most notable of these being the Smithsonian Institution. In 1993, an expedition from Washington University in St. Louis began what would be a 30+ year project in the Uinta and Duchesne River Formations, with the goal of collecting small mammals. These latest expeditions have amassed one of the largest assemblages of Uintan mammals from the Rocky Mountain region.

The Uinta Basin Project, as we refer to it today, has been ongoing and led by various institutions. Washington University in St. Louis, led by Dr. D. Tab Rasmussen began expeditions in 1993 in the Uinta Formation looking for small mammals. Rasmussen’s work was continued by his colleague Dr. Dana Cope (College of Charleston) and Rasmussen’s former graduate student Dr. Beth Townsend (Case Western Reserve University and now, Midwestern University). More recent investigations brought on a full team of specialists to fully collect and describe the fossil faunal diversity and measure and describe the geology of the middle Eocene formations of the Uinta Basin (Uinta and Duchesne River Formations). Currently, our multi-disciplinary team of colleagues is leading a series of studies to understand how vertebrates respond to local and regional shifts in climate. Importantly, most of our team of investigators has been trained in the Uinta Basin during their undergraduate and graduate careers.