This paper presents a model of global timber markets that captures the evolution of a broad array of forest resources and timber market margins over time. These margins include the inaccessible northern and tropical margins, plantation establishment, and timberland management. A baseline case is presented and discussed. Five alternative scenarios are then presented. These scenarios allow us to consider several important questions about timber market behavior and the future supply of industrial fiber: (1) What happens along the northern and the tropical inaccessible margins? (2) What role do timber plantations play? and (3) How do shifts in management intensity interact with market forces? The baseline case suggests that both prices and harvests rise over the next 150 years, with most of the increased harvest coming from existing and newly established plantations. Future gains in harvests result mainly from intensification of management, through additional plantation establishment and higher levels of management on selected forests rather than higher harvests in currently inaccessible forests. Prices and harvests are most sensitive to alternative demand and plantation establishment scenarios, and less sensitive to costs of accessing extensive forests.