Technical Abstract: The enzyme status of soil influences mineralization kinetics, and thus, the supply of nutrients to plants. I quantified urease, asparaginase, glutaminase, aryl-phosphatase, and aryl-sulfatase activity in an Artemisia tridentata ecosystem northeast of Reno, NV. Enzyme activity was evaluated by depth (0-5 cm, 5-10 cm, 10-20 cm), microsite (A. tridentata, Agropyron desertorum, Bromus tectorum, microphytic crust, shrub interspace), and treatment (grazed and ungrazed). For most enzymes evaluated, there was a significant depth x microsite interaction. In general, enzyme activity declined with depth. Moreover, the interspace microsite usually had the lowest enzyme activity. In the 10-20 cm depth increment of the B. tectorum microsite, the grazed treatment had significantly higher urease activity as compared to the ungrazed treatment. Enzyme activity may be an important component in the health of rangeland soil. Future research should more intensively address temporal and microsite aspects of soil enzyme activities.