In western North America, the Western Stemmed Tradition (WST) is contemporaneous with, but technologically different from, the Clovis Paleoindian Tradition as initially defined from the Great Plains and American Southwest. The foundational principles of WST lithic technology have not been as clearly delineated as those of their fluted and unfluted Paleoindian Tradition technological counterparts, largely due to the paucity of extensive WST lithic assemblages recovered from intact buried contexts. Recent excavations at the Cooper's Ferry site, located in western Idaho, revealed a stratified series of WST components spanning the late Pleistocene to early Holocene periods. The study of these components offers a unique opportunity to evaluate current expectations about WST lithic technology. Here, we describe the discovery, context, and contents of a new cache of 14 WST projectile points from the Cooper's Ferry site that provide clues about WST lithic reduction patterns and the design of early stemmed projectile points. We employ several novel methods of lithic analysis based on three-dimensional digital scanning technology and geometric morphometry and, in doing so, seek to demonstrate new ways of studying stone tools through the use of next-generation methods of lithic analysis applied to exploring the poorly known technological details of the WST.