Because of the normative and subjective nature of the terms sustainability and sustainable development, solutions tend to be applicable for specific regions but not the whole of society. Thus, it is imperative understand better how community stakeholders and decision makers define the concept of sustainability. Not only will greater understanding of such definitions add to our understanding of nature-society relations, but also in certain contexts, this understanding may help to promote realistic and effective decision-making at local levels. The objective of this study was to determine how amenity-driven gateway communities surrounding Yellowstone and Grand Teton National parks define, conceptualize, and perceive sustainability, and if those perceptions varied between time in residence, community of origin, or role within the community. Thirty-five key informant interviews were conducted with decision makers within the Greater Yellowstone Ecosystem to meet the study objectives. Throughout study communities, definitions of sustainability focused on the environment, the economy, and multi-generational thinking, and it is believed that these similarities can be the starting point for communication and collaboration among gateway communities, the long-term sustainability of their individual communities, and the collective resource upon which they all depend, the Greater Yellowstone Ecosystem.