Relationships between the development of desired conditions based on today’s social values, and an understanding of the historic range of variability (HRV) are key to the implementation of ecosystem management. Relevant to the discussion are wildlife habitat values, forage production, economics related to wood resources, aesthetics and visual quality, changes in predicted and actual fire intensity especially within the urban interface. Potential risks to air quality, and risks associated with changes in insect and pathogen activities, and significant degradation of soil and aquatic resources are also discussed. The HRV for western larch and ponderosa pine cover types are described in terms of vegetation composition, structure, pattern and areal extent at broad- and midscale. They are also described in terms of broadscale fire regimes and mid-scale processes mediated by insects and pathogens.