The Hydraulic Fracturing Test Site (HFTS) is a field-based hydraulic fracturing research experiment located in the West Texas Permian (Midland) Basin.  The HFTS includes $25 million of hydraulic fracturing research, centralized around eleven horizontal wells fractured with over 400 stages in the Upper and Middle Wolfcamp formations as well as two recompleted legacy wells. Comprehensive field data was collected at the test site, including advanced diagnostics to measure hydraulic fracture properties.  To supplement the fracture diagnostics, a one-of-a-kind high-angle core well was drilled through the created hydraulic fractures and 600 feet of core was recovered.  Based upon observations made from the acquired core, the understanding of hydraulic fracture propagation and effectiveness of proppant placement is challenging current thinking.  Hydraulic fracturing experiments also demonstrate the effectiveness of variable pump rate fracturing in improving perforation performance and near-wellbore connectivity, and impact on production.  The presentation will provide an overview of the project, including details of the test site, experiments performed, and selected results.