The historical role of naturally occurring fire in shaping the character of many American landscapes has become an accepted ecological principle. Prior to the coming of the Europeans, natural fires had a major influence in producing a variety of vegetational mosaics. Fire suppression policies of the 20th century, however, significantly changed the evolution of many landscapes compared to what would have occurred had natural fires been allowed to continue. Although natural fires can no longer be allowed to burn in many places because of resource values or danger to the public, such fires may be permitted in many wildernesses and National Parks under specified conditions -- if they achieve certain objectives.
United States Department of Agriculture, Forest Service, "Visitor Attitudes Toward Wilderness Fire Management Policy -- 1971-84" (1986). Wildfires. Paper 2.