Interviews of tribal and nontribal residents of the Flathead Indian Reservation in Montana, U.S., were conducted to contrast the meanings that different cultures attach to the Mission Mountains Tribal Wilderness. Legislation that created a national system of wilderness areas (in 1964 and still growing) was conceived, supported, and enacted by a fairly distinct social group generally residing in urban areas and schooled in modern civilization's scientific model and relationship with nature. The places this legislation protects, however, provide many other poorly recognized and little understood meanings to other parts of society. There is a link between indigenous people and nature that is not described well in this legislation or management policy in most places. The Wilderness Act suggests that these protected areas should be "untrammeled," or unmanipulated, unfettered, when in fact it is common knowledge that, for most areas in North America, indigenous people have intervened, with respect, for generations. The Mission Mountains Tribal Wilderness in Montana, though not part of the National Wilderness Preservation System, was designated to protect many of these same values but also extend to protect important cultural meanings assigned to this wild landscape. Protecting the relationship between indigenous people and relatively intact, complex systems, which we commonly refer to as wilderness in North America, can be an important contributor to sustainability of the landscape and cultural heritage.