Long interval fire frequency regime from an upper elevation forest composed of red fir, western white pine, and small amounts of lodgepole pine. Fires are typically understory burns in red fir forest although small-to-moderate sized patches of overstory mortality can occur.

Red fir trees are moderately tolerant of low intensity fire with larger trees having fairly thick fire resistant bark. In contrast, both western white and lodgepole pine have relatively thin bark that provides poor protection from fire. Thus they gernerally suffer proportionally higher mortality rates than red fir. © Photo by Anthony Caprio.