The regions surrounding many nature reserves are growing rapidly in human population size. Such population increases raise question as to role of ecosystem quality in attracting new immigrants and the consequences of increasingly intense human land use on ecosystem quality. The goal of this study is to quantify changes in biodiversity, land use, and human socioeconomic performance in the Greater Yellowstone Ecosystem (GYE) over the past 23 years and to test hypotheses on interactions among these ecological and human factors. Objectives of the study are: 1. Quantify changes in biophysical gradients, biodiversity, and land use and socioeconomic factors across the GYE from 1972-1996. 2. Test hypotheses on interactions among biophysical gradients, biodiversity, and socioeconomic patterns. 3. Assess current and future risk to ecological hot spots and potential for restoration. 4. Develop an approach to monitor ecological and human interactions. 5. Communicate results to stakeholders. Here, we report progress from September 1997, when funding began, through April 1998. A first step was to define the study area boundaries based on ecological and socioeconomic factors. The resulting 100,000-km2 study area includes a gradient in land use from lowland urban and agriculture to high elevation nature reserves, and includes 20 counties. We then delineated one of these counties (Gallatin) as a pilot study area where we will focus the initial trend assessment and hypothesis testing. After methods are refined in the pilot study area, analyses will be extended to the entire study area.