Developed areas within these parks, including campgrounds, roadways, visitor centers, and administrative sites are managed to provide recreational opportunities for visitors and as an operation base for park management in as natural a setting as possible. The overall goal of managing vegetation in these areas is to restore and/or maintain a healthy, vigorous vegetative community that approximates the "natural" state, given the constraints of past and present human intervention, while providing a safe environment for human use and enjoyment. Because trees often contain structural defects that contribute to their failure and constitute a hazard to adjacent human use, the preservation of these trees must be sensitively balanced with the need to provide for visitor safety. As part of the tree hazard management program, foresters evaluate trees in developed areas for structural soundness and determine whether they pose a significant risk to people or buildings. In such cases, a specially trained crew of tree workers removes those trees or parts of trees that are likely to fail and cause harm to life or property.