Ensuring combat readiness while managing the environment that supports the training can be a time-consuming and dynamic challenge. An easy-to-use ArcView GIS-enabled expert system is being applied by range control and environmental personnel to address this challenge. This system operates as two discrete but connected modules, each accessing spatial data. The first encodes multidisciplinary environmental knowledge as "rules" (chains of cause and effect) for different activities. Unlike conventional constraint mapping techniques, the system predicts and displays activity- and site-specific impact zones and recommends appropriate mitigation and monitoring strategies. The second module allows range personnel to book, schedule, deconflict, and manage the safety conditions on training areas and ranges. This paper discusses functional aspects of the system and example applications including military training area scheduling and management, environmental impact assessment decision support, and natural resource management planning.