From the Introduction...'Fire is the single most important ecological disturbance process throughout the interior Pacific Northwest (Mutch and others 1993; Agee 1994). It is also a natural process that helps maintain a diverse ecological landscape. Fire suppression and timber harvesting have drastically altered this process during the past 50 to 90 years. Natural resource specialists generally agree that the forests of the interior Pacific Northwest are less healthy, less diverse, and more susceptible to larger and more destructive wildfires as a result of this human intervention (Everett 1994). Analysis of current and historical aerial photographs for the East Side Forest Health Assessment (Huff and others 1995) indicates there has been an increase in forest fuels, crown fire potential, and smoke production potential since the 1930*s brought on by selective logging and fire suppression activities. In addition, acres burned by wildfires across Washington and Oregon on USDA Forest Service lands have been increasing (fig. 1). Prescribed fire, often in combination with other management techniques, can be used to restore wildland forests to a more sustainable structure while simultaneously reducing the potential for catastrophic wildfires (fig. 2). Unfortunately, prescribed fire runs contrary to current Federal and state environmental laws because any fire event has the potential to degrade ambient air quality, impair visibility, and expose the public to unhealthy pollutants. Air regulatory agencies and the public must come to understand the complex tradeoffs between increased prescribed fire, inevitable wildfire, forest health, visibility impairment, and public exposure to smoke before this issue can be resolved. To improve this understanding, land managers and researchers have cooperated in two development activities. The first activity we discuss in this paper is called the Wildfire/Prescribed Fire Tradeoff Model (FETM), a stochastic simulation model to evaluate the tradeoff between prescribed fire and wildfire emissions over time. The second activity we present is an assessment of prescribed fire and wildfire emissions over time for 337 watersheds within the Columbia River Basin.' From the Conclusions...'Air quality regulations have the potential to seriously limit land management actions that use fire for ecological restoration. Air regulatory agencies, land managers, and the public must understand the complex tradeoff issues that the reintroduction of fire poses in terms of forest health, wildfire occurrence, visibility degradation, and human health. The burden of proof is with the land manager to provide estimates of the potential impacts from fire use scenarios and monitor for those effects. The best opportunity to keep fire as a viable tool in ecological restoration involves (1) fostering an atmosphere of cooperation between regulatory agencies and the public and (2) providing a sound impact analysis of management activities.'