The process of updating the Pinal model geology was begun in 2007, and had not been addressed since Modeling Report No. 2 (Corkhill and Hill, 1990). The purpose of this provisional report is to document the data collection activities and findings of the hydrogeologic framework of the study area. This report will be finalized after the Pinal Active Management Area (AMA) Regional Groundwater Flow Model report which documents the update and recalibration of the groundwater flow model in Pinal County have been completed.