Habitat distribution and stand dynamics of whitebark pine (Pinus albicaulis) within the whitebark pine zone of the Mount Washburn massif, Yellowstone National Park were investigated as part of a study of relationships among grizzly bears, red squirrels, and whitebark pine. Distribution of whitebark pine and whitebark pine habitat types was positively associated with increased site coldness and wind exposure. Subalpine fir (Abies lasiocarpa) and Engelmann spruce (Picea engelmannii) were relatively intolerant of wind exposure. Whitebark pine and lodgepole pine (Pinus contorta) were principal seral species and competitors in the whitebark pine zone. Lodgepole pine replaced whitebark pine on the warmest sites of the zone. Whitebark pine was climax because of its ability to tolerate extreme site conditions rather than shade, and so was climax only on sites with the most extreme wind exposure at high elevations where other tree species could not survive. On the harshest sites whitebark pine recruitment into the overstory was near zero, but proportionately increased with site amelioration. Fire frequency in our study area was estimated to be 250 years, although stand replacement fires occurred somewhere in our study area at average 80-year intervals.