Some real forest management problems require integer value (yes/no, 1,2,3, etc.) assignments to potential decisions. For example, when a stand of trees is being considered for a harvest activity, often the entire stand of trees will be applied the activity (in practice) rather than some arbitrary portion of the area. Mixed integer programming is a solution process that is very similar to linear programming in design, yet assumptions regarding the values some decision variables can be assigned may be different. While linear programming requires all values assigned to decision variables to come from the set of continuous real numbers, in mixed integer programming, some of the variables can only be assigned integer values. Pure integer programming is a case where all decision variables need to be assigned integer values. As was noted in Chap. 1 , contemporary forest management problems might include integer decision variables, particularly when the adjacency and green-up of harvest areas are recognized in the model system. This chapter describes the general application of common mathematical (exact) methods for solving integer or mixed integer programming problems.