According to the National Interagency Fire Center (NIFC), there were 40 large wildfires burning in the western United States on August 20, 2001. (A 'large fire' is defined as being uncontained and scorching more than 100 acres.) Altogether, these fires have consumed almost half a million acres of forest and rangelands. More than 28,500 firefighters and support personnel have been deployed to battle the blazes, with particular emphasis on the Pacific Northwest where drought conditions are in effect. The true-color image above shows a number of active wildfires (red boxes) burning in Washington. This scene was acquired on August 18. The fires have produced a large, greyish shroud of smoke and haze covering much of the region. The brighter, whiter streaks running north-south are overlying clouds. Today, the U.S. Forest Service and NIFC are using a new tool to help them monitor active wildfires across the entire United States and decide how best to combat them. The regional perspective provided by the satellite, as well as the superior spectral and spatial resolution of the sensor's data, allow fire experts to more accurately determine the intensities of fires and better estimate their effects on regional air quality. These data also help scientists monitor plant regrowth in areas previously affected by wildfire.