Abstract: The McClellan-Kerr Arkansas River System (MKARNS) is a major inland waterway that begins at the Port of Catoosa in Tulsa, OK, and travels to the confluence of the White and Mississippi Rivers. Over the years, many structures have been built to help control overland flow between the White, Arkansas, and Mississippi Rivers. These structures have required a significant amount of rehabilitation, which has resulted in high maintenance costs. The US Army Corps of Engineers and the Arkansas Waterways Commission conducted the Three Rivers Southeast Arkansas Feasibility Study (also known as the Three Rivers Study). The Three Rivers Study focused on providing long-term dependable navigation in the MKARNS. From this study, a proposal was developed that included a 1,000 ft reopening of the Historic Cutoff and a reinforcement of several areas near the White River. In 2019, the US Army Engineer Research and Development Center Ship/Tow Simulator was used to perform a navigation study to ensure the proposed modifications did not negatively impact navigation on the White River section of the MKARNS. Assessment of the proposed modifications was accomplished through analysis of ship simulations completed by experienced pilots, discussions, track plots, run sheets, and final pilot surveys.