This map depicts the geology of the Land 7 ½' Quadrangle, which is located in the upper San Pedro Valley a few miles north of the U.S. –Mexico border. The quadrangle covers much of the piedmont west of the San Pedro River and much of the San Pedro River corridor. The quadrangle also covers about 10 miles of the San Pedro Riparian National Conservation Area along the river, and bedrock hills and a small portion of the piedmont east of the San Pedro River. The geology of the quadrangle is diverse and includes Cretaceous sedimentary and igneous rocks, extensive exposures of the upper part of the late Cenozoic basin -filling deposits, and Quaternary surficial alluvium deposited by tributary streams and the San Pedro River. This map is one of 7 1:24,0 00-scale geologic maps that have been completed recently in the upper San Pedro Valley. Other maps cover the Fairbank (Ferguson et al, 2006), Lewis Springs (Pearthree et al. 2005), Saint David (Youberg, 2005), Huachuca City (Pearthree, 2003), McGrew Spring (Shipman and Ferguson, 2003), and Benson (Youberg et al, 2004) quadrangles. This mapping was completed under the joint State -Federal STATEMAP program, as specified in the National Geologic Mapping Act of 199 2.