The Department of the Navy has issued a Notice of Intent to prepare a Supplemental EIS/Overseas EIS for the Mariana Islands Training and Testing (MITT) program, supplementing the 2015 MITT EIS/OEIS and the 2020 MITT SEIS/OEIS. The Proposed Action is to continue military readiness activities including training, testing, and range modernization within the MITT Study Area encompassing in-water areas of the Mariana Islands Range Complex and adjacent high seas. Three alternatives are analyzed: Alternative 1 (representative year activity), Alternative 2 (maximum annual activity), and No Action. Key concerns include impacts to marine mammals and protected species from active sonar and explosives. The 45-day scoping period runs June 7 to July 22, 2025, with a Draft SEIS/OEIS expected in winter 2026.1