ROUTING F.V. HAYDEN IN RELATION TO HIS COLLECTIONS OF 1853-1866 ON HIS 1869 GEOLOGIC MAP OF THE MISSOURI-YELLOWSTONE RIVER DRAINAGE SYSTEM: PLACING LOCALITIES IN TIME AND SPACE BASED ON EXPLORATION AND MUSEUM RECORDS

Documenting F.V. Hayden’s collecting is limited by his generalized locality data and lack of daily journals. Correspondence indicates he kept copious field notes. Hayden remarked on the importance of fossil documentation, but we are challenged by the brevity of what he left.

A comprehensive undertaking places the many (type) specimens collected by Hayden during his youthful-antebellum days in Nebraska Territory. Hayden’s routes and known locations were placed on his 1869 geologic map of the drainage system of Missouri and Yellowstone Rivers (W.F. Raynolds’ base map). Routing and locations are based on Hayden and his association with day-to-day trip journalists Meek (1853), Vaughan (1854, 1855), Hayden (1855, 1866), Warren (1855, 1856, 1857), Galpin (1855a, b), Snowden (1859), Raynolds (1859, 1860), and Mullins (1860). A reconstructed Raynolds map adds data from Warren (and others), along with Hayden side trips. Hayden’s noted wanderlust (Warren and Raynolds) suggests some localities referred to landmarks may be just approximations. Reference information is given for each camp and locality.

The routes and day locations of trip participants were compared with 1) Smithsonian Department of Paleobiology specimen numbers and 2) published locality data. As examples, commencing in about 1861, Hayden’s “Cretaceous. Mouth Judith River” and “Jurassic. South W. Base Blk. Hills” were entered for specimens USNM-PAL 176-193 (JHH L3062) and 194-206 (JHH L1342). Published data verified museum entries (e.g., Meek and Hayden, Meek, Leidy, others, and cataloged nontype Hayden specimens). A wealth (if sometimes cryptic) of correlatable data exist to place Hayden where he thought he was geographically on his 1869 geologic map. L3062 is one of five closely spaced Hayden locations bearing marine, brackish, and freshwater taxa collected on two trips and from as many as five lithic units. L1342 constitutes multiple localities from marine units and a Jurassic or Lower Cretaceous Morrison or Lakota Formation occurrence of a freshwater unionoid. Warren’s 1857 route is relatively well constrained by tributaries of the Cheyenne River. Hayden, however, had the opportunity to collect from a number of fossiliferous lithostratigraphic units. The approach presented, although not definitive, provides likely limitations on Hayden’s fossil locations.