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Ecological Site Descriptions (ESD) synthesize information concerning soils, hydrology, ecology, and management into a user friendly document. A crucial component of an ESD is the state-and-transition model (STM) that identifies the different vegetation states, describes the disturbances that caused vegetation change, and the restoration activities needed to restore plant communities. Many landscape-scale management planning activities such as fire rehabilitation occur at scales far larger than the individual ecological site scale therefore we have developed a robust method for aggregating ecological sites into groups that respond similarly to the same disturbances. An expert team of range and soil scientists follows a multi-step approach to response group development: (1) review MLRA characteristics, (2) establish guidelines for STM development, (3) sort ESDs into dominant cover type groups, (4) sub-divide cover type groups by climate, production and soil properties, (5) evaluate response to disturbances, and (6) define the soil-site concept for each group and select a modal ecological site. A draft STM is developed for the modal site prior to field investigation. The end product is a Disturbance Response Group (DRG) consisting of multiple ecological sites with one robust STM. The DRG can be mapped spatially within a MLRA and often consists of millions of acres. This technique is ecologically sound and provides management with a landscape-scale tool for multiple applications including monitoring, habitat restoration, fire rehabilitation and allotment planning.