The sagebrush steppe ecosystem type in the western U.S. is undergoing rapid change due to a combination of influences including: invasion of non-native plants, especially annual grasses such as cheatgrass; catastrophic wildfires; and encroachment of pinyon pine- and juniper-dominated woodlands. Due to these environmental stressors that result largely from human management actions, as much as half of the land area dominated by sagebrush has disappeared. Great Basin sagebrush communities are now identified as one of the most threatened types in North America. Accordingly, various land management agencies have launched efforts to restore sagebrush-steppe ecosystems and to reduce the extent, frequency, and intensity of wildfires that threaten both native plant communities and human communities. The Sagebrush Steppe Treatment Evaluation Project (SageSTEP) was initiated in 2005 as a five-year interdisciplinary research project that would: identify conditions that determine the transition between healthy and unhealthy sagebrush plant communities; evaluate ecological and other effects of alternative land management practices in landscapes threatened by annual grass invasion or woodland encroachment; and facilitate the flow the information gathered to inform effective management of sagebrush communities in human-influenced landscapes of the Great Basin. The research team includes scientists from five universities and four federal government agencies, representing a wide range of scientific disciplines, working collaboratively at experimental sites covering the entire region from central Washington to southwestern Utah. Members of the SageSTEP research team will present findings from our ongoing research activities. Presentations will exemplify the breadth of research questions and approaches that are being used to gather ecological knowledge relevant to management of the sagebrush steppe for natural objectives, such as restoration, as well as human objectives such as range livestock production. Presentations will focus not only on key biotic and abiotic components of sagebrush-dominated ecosystems, but also on the ways in which ecological knowledge generated through this research can be used and interpreted by land managers as well as the human stakeholders whose concerns must be weighed in ecosystem management.