In the Western United States, many of the forests have too many small trees. These small trees increase the risk of wildfire. Forest managers, therefore, want to remove the small trees. Some scientists believe these small trees may be a good source of fuel. The scientists in this study wanted to compare the costs of and revenues gained from using the small trees for thermal energy with the cost of piling and burning the small trees. Topics: Engineering and Forest Products, Fire, Wilderness, Computer Model, Cost Analysis, Diameter at Breast Height (DBH), Forest management, Fuels Reduction.