This engaging four-hour program delves into the planning, execution, and outcomes of the historic 1923 survey of the Grand Canyon, led by Colonel Claude Birdseye and his team. At a time when only 27 individuals had successfully traversed the entire canyon, this survey marked a significant milestone in exploration and mapping. The presentation will explore the "who, what, when, and why" behind this monumental effort, shedding light on the role of the Chief of the Topographic Mapping Division of the USGS and the survey’s traversal through the Marble and Grand Canyons. Attendees will gain a deeper appreciation for the challenges and achievements of this landmark expedition.