Abstract
Mountain goats (Oreamnos americanus) are not thought to be historic natives to the Greater Yellowstone Ecosystem. They occurred in the area before 10,000 B.P. but all evidence indicates they were extirpated from the area by the time Europeans arrived. The Idaho Department of Fish and Game and the Montana Department of Fish, Wildlife, and Parks introduced goats into the area in the mid 1900's. Goats have expanded in numbers and range and are occasionally seen within Yellowstone and Grand Teton National Parks. There is concern that their presence in the Parks might negatively impact native plants and animals. This study assessed the current distribution of mountain goats and their potential impact on fauna and flora of the Parks. The current distribution of mountain goats in the Greater Yellowstone Ecosystem was determined by consulting area resource managers, perusing sighting records, and conducting field surveys. The potential impact of goats on the fauna and flora of Yellowstone and Grand Teton Parks was assessed by compiling all available information on mountain goat behavior and ecology.