Modeling the potential spatial distribution of beef cattle grazing using a Geographic Information System

Data regarding grazing utilization in the western United States are typically compiled within administrative boundaries (e.g. allotment, pasture). For large areas, an assumption of uniform distribution is seldom valid. Previous studies show that vegetation type, degree of slope, and distance from water largely determine the distribution of livestock. We demonstrate how range managers can use Boolean logic and a Geographic Information System (GIS) to develop models that predict which areas beef cattle are most and least likely to graze. The models show that approximately 60% of the state of Oregon has potential for rangeland grazing. The results compare favorably with the 1992 census of beef cattle.