Although sugar pine has been the most affected and studied of these, rust is also present at low levels in some whitebark pine stands. Whitebark pine cannot maintain its functional role in mountain ecosystems unless areas suitable for its regeneration are available across the landscape. It is clear that the blister rust epidemic in whitebark pine has not yet stabilized, even in regions with the longest history and highest infection levels of rust. The most likely prognosis for whitebark pine in sites already heavily infected with rust is that they will continue to die until most trees are gone. In the future, whitebark pine trees will be all but absent in most areas, and small, isolated populations will be lost until rust-resistant types evolve.
Winter comes to a whitebark pine stand in Yellowstone National Park, Wyoming.