Ferdinand Hayden's 1868 survey of the Wyoming and adjacent territories was a small, largely ignored survey; but it was important to the history of geology and the American West. The discovery of new material related to Hayden's 1868 survey, including a personal diary of one of the assistants on the survey, James Carson, provides critical information that allows the survey's story to be fully articulated and analyzed for the first time. Most of the expedition's activities took place in southern Wyoming and were closely intertwined with one of the most noteworthy events in U.S. history—the building of the transcontinental railroad. The railroad's construction activities caused Hayden to have serendipitous encounters with legendary army generals, businessmen, politicians, photographers, geologists, and thieves, many of whom significantly changed the course and scope of the survey. Some of these people included James Hall, General John Gibbon, Frank Blair, Louis Agassiz, Thomas Durant, and William Gilpin. Despite severe underfunding and the lack of a military escort, the survey persevered and surpassed its original goals. It produced the first descriptive stratigraphic-structural profile across the Rocky Mountains from Cheyenne to Salt Lake City and, somewhat unknowingly, the first documentation of dinosaur tracks in western North America. The overall success of the expedition allowed Hayden to expand his surveys and helped solidify his reputation as an important pioneering American geologist. However, the field reports of the survey and Hayden's zeal to appease important people may have helped to prevent his hoped-for appointment as the first director of the U.S. Geological Survey.