Previous research has shown that grazing cattle tend to congregate in riparian zones of pastures to obtain water and shade for thermoregulation. However, problems associated with thermoregulation may be increased because of the presence of endophyte-infected tall fescue in pastures. Defining relationships between cattle distribution, such pasture characteristics as size, shape, shade distribution, botanical composition, and climatic factors related to heat stress, will provide the basis for development and implementation of management practices that minimize nonpoint source pollution possibly associated with grazing cattle.