Forest resource management planning began in the United States at the turn of the nineteenth century with an emphasis on timber production, sustained yield, and maximum timber growth. A set of well-documented procedures, philosophies, rules, and understandings developed within the forestry profession on the reasons for and requirements of a professionallydeveloped forest resource management plan. For most of the next decade, this framework controlled the development of timber-oriented forest management plans. In the late twentieth century, the forest resource management plans became stewardship- or sustainability-oriented. A broader expansive framework that stressed sustainable forest management developed. However, the framework of both types of plans is fundamentally the same. The natural resource being manipulated is still timber and that is the variable the management plan still focuses on. The set of fundamental underpinnings to the forest management plan has not changed. We describe these underpinnings in terms of both types of forest management plan, as they have remained unchanged over time. Also addressed are the questions of who are the forest owners that plan and what are the differences in the type of forest management plans they prepare.