In 2009, the National Park Service (NPS) completed an elk management plan and environmental impact statement that called for a 50% reduction of elk numbers at Wind Cave National Park, South Dakota. The plan prescribed modification of the park fence to achieve a change in elk distribution, leading to increased hunting mortality outside the park. Because changes in elk numbers are difficult to track and may result from myriad influences, population estimates may not accurately indicate the success or failure of management actions. Therefore, the USGS and NPS are using GPS satellite telemetry collars to monitor elk movements and survival, and to compare the distribution, movements, and population dynamics of park elk before and after implementation of the elk management plan. Data obtained with GPS satellite telemetry collars are enabling USGS scientists to determine with certainty whether management actions are having the desired effects on distribution, leading to concomitant increases in hunting mortality.