A field excursion following the route described herein was conducted as a part of the curriculum of the 6th Ground Water Short Course, which was held by the Geological Survey at the University of Arizona in April 1954. The route log and descriptive text were designed to provide a general background of the ground-water situation in the Upper Santa Cruz Basin, a few of the geologic features that affect the occurrence of ground water, and some of the historical highlights of the region.