Logging and forest thinning operations generate large amounts of residues in the form of small trees, branches and foliage that are usually left on the ground to decay or are burned. These resources are readily available, but it is uneconomical to remove them from the forest. The potential utilization of these resources was investigated for western juniper. This species is invading rangeland in the Interior West, altering the ecology of the land, and farmers are being encouraged to remove it. However, limited markets for the wood make removal costly. Developing uses for other parts of the stem could make removal more economically attractive. Western juniper foliage and twigs were steam distilled to obtain essential oils which were tested for their activity against subterranean termites and fungi. Residues from the steam distillation were pretreated with dilute sulfuric acid and digested with enzymes to determine their digestibility. The goal was to determine if an integrated operation involving steam distillation to remove essential oils, followed by enzymatic digestion of extraction residues was feasible. Essential oil recovery from foliage averaged 0.77% wet weight, while yields from twigs were about 0.13% wet weight. Foliage essential oil showed high antifungal and termiticidal activities at the concentrations tested. Total sugar yields from foliage extraction residues (40-55%) were higher than those obtained from branchwood residues (15-25%). The highest yields were obtained at 121°C and 1 hour pretreatment in 1% sulfuric acid. These results show that an integrated operation involving steam distillation of western juniper foliage to remove essential oil and enzymatic digestion of extraction residues is technically feasible. Additional work to determine the optimum distillation and pretreatment conditions for foliage would be needed. / Graduation date: 2012