The McGrew Springs 7.5' Quadrangle is located in northwestern Cochise County about 45 miles southeast of Tucson, Arizona and lies south of the town of Benson. The western portion of the map encompasses a portion of the eastern flank of the Whetstone Mountains which is part of the Coronado National Forest. Kartchner Caverns State Park is located in the northwest corner of the map. The majority of the map area is covered by Quaternary fan and Tertiary basin fill deposits. Bedrock and surficial geology in the study area were mapped between October, 2002 and June, 2003 as part of a multiyear mapping program directed at producing geologic map coverage for the Karchner Caverns State Park and surrounding areas. Quaternary and late Tertiary deposits in the McGrew Springs 7.5' Quadrangle were partially mapped by Gray (1965) however this map does not separate the quaternary deposits from each other. Multiple phases of Quaternary alluvial fans top late Tertiary valley fill. Large outcrops of valley fill are exposed in the southeastern portion of the map which could be related to structure, however, there was no direct evidence for this structure in the mapped deposits.