This report was developed to provide a user guide and tutorial for applying the Training Range Environmental Evaluation and Characterization System (TREECS(TM)). The purpose of TREECS(TM) is to provide the Army with varying levels of capability to forecast the fate of and environmental risk from munitions constituents (MC), such as high explosives (HE), present in and transported from firing/training ranges to surface water and groundwater. The overall objective is to provide Army environmental specialists with tools to assess the potential for migration of MC into surface water and groundwater systems and to assess range management strategies to protect human and environmental health. Tier 1 consists of screening-level methods that assume highly conservative, steady-state MS loading and fate. Tier 2 provides time-varying analyses. This report provides information to assist the user in learning how to apply TREECS(TM) for Tier 1 and 2.