Each of these fires has a written prescription, a detailed plan on the type of weather, staffing, and other conditions which must be met before the fire can be set. If conditions change and the fire is no longer within prescription, it will be immediately extinguished. For example, strong winds are common in Big Bend. A prescribed fire is postponed or suppressed if high winds are forecast for the park region. The National Park Service is also concerned about smoke and how it impacts human health and air visibility.
Winds sometimes shift direction after a prescribed fire is started.
If those winds bring large amounts of smoke to areas of high human use, the fire is put out. Big Bend's Fire Management Officer sets up a schedule for prescribed burns throughout the park. Such fires were ignited in the Chisos Basin in September 1997 and near the Panther Junction Visitor Center in April 1998. Both fires were about 70 acres in size and were ignited to reduce hazardous fuel loads. Visit those sites to view the reductions in flammable materials and regrowth of vegetation.