This study examines bifacial technology change at the Knob Creek site (12HR484) in Harrison County, Indiana, from the Late Archaic to Early Woodland periods. Through a statistical and attribute analysis of 2,620 lithic flakes it was possible to detect changes in the lithic reduction process over time. The analysis demonstrates that soft-hammer percussion becomes more prevalent during the Early Woodland component of the site. This is a significant change from the hard-hammer percussion industry of the Lower Late Archaic. The Terminal Archaic Riverton component in this study offers one of the few detailed flake-by-flake analyses for this poorly understood lithic tradition originally identified by Winters (1969) in the Wabash River Valley.