Coordination of air and surface fires with maneuver provides an ideal target for simulation training due to the limited availability, high cost, and risk associated with live fire exercises. Current simulation systems provide task-oriented training to operators, but no opportunity to practice communicating and coordinating with other agencies. This thesis uses the Distributed Simulation Engineering and Execution Process to guide the creation of a simulation environment that addresses this training capability gap by demonstrating interoperability of simulations for ground observers, close air support, constructive surface fires, and communication tools in a realistic combined arms scenario. A simulation environment featuring Bohemia Interactive Simulations VBS4, Lockheed Martins PREPAR3D, and Battlespace Simulations Inc.s MACE was developed using the Distributed Interactive Simulation (DIS) standard along with ASTi Voisus communications software. Although a research virtual private network (VPN) was available, DIS broadcast communications could not be supported between VPN clients. The simulation environment was run on a local network and distant users utilized remote desktop connections. Although VBS4 suffered performance issues and PREPAR3D is not ideal for close air support, MACE and ASTi Voisus performed well and the simulation environment was successful. For physically distributed training a High-Level Architecture (HLA)or multi-architecture federation is recommended.