Animal foraging and distribution problems are a major source of controversy on public and private rangelands throughout the western United States. As wild and domestic grazing animals forage across landscapes, they influence biotic and abiotic components of rangelands through the plant species they utilize and the habitats they occupy. Unmanaged grazing can degrade economic and ecological values of watersheds. The control of animal foraging and distribution patterns is therefore essential to successful rangeland and grazing management.