The process analysis approach was chosen for modeling the joint product nature of timber supply. Considerable emphasis was placed upon defining model components that would be required for developing a positivistic model of timber supply. An empirical application of the proposed linear programming model to Eastern Virginia simulated the impacts of increased fuelwood prices on the timber market system in 1976. The empirical application of the model indicated an ability to simulate many of the complex market interactions inherent in timber supply. Fuelwood was found to act as both a production complement and a production competitor with the conventional forest products, depending upon the range of prices analyzed. Fuelwood price was also found to act as a demand shifter for roundwood outputs of the forest.