To prevent being eaten, some plants create compounds that are toxic to herbivores, and herbivores respond by creating new ways to metabolize these toxins. For example, sagebrush produces bio-defensive terpenes to deter foraging by sage grouse. A recent investigation to characterize plant secondary metabolites (PSM's) in sagebrush resulted in a correlation between terpene concentration and nutritional content in local sagebrush to the habitat selection of sage grouse. This study identified many of the terpenes in sagebrush, but not all of them. A highly volatile and elusive terpene is suspected to be an important PSM that significantly affects sage grouse foraging. The purpose of the current work is to identify the structure of this PSM, as well as other unknown PSM's in sagebrush, to better understand their role as chemical warfare agents to defray foraging. Sagebrush extracts will be analyzed and components identified using Gas Chromatography-Mass Spectrometry (GC-MS).