Reeve’s first cross-continental trip, organized by Yale University Professor Othniel C. Marsh as the Yale Scientific Expedition of 1870, took Reeve through the Western United States in search of geological specimens, where he visited Nebraska, Colorado, and California in the company of guide William (Buffalo Bill) Cody.  Reeve took several samples of rock and flora as part of the expedition including materials from what would later become Yosemite National Park.