Based on NMFS’s receipt of an application from the United States (U.S.) Department of the Navy (Navy) for incidental take regulations and a Letter of Authorization (LOA) under the Marine Mammal Protection Act, this action proposes regulations to govern the unintentional taking of marine mammals incidental to replacement and maintenance of the Ammunition Wharf marine structure at the Naval Magazine (NAVMAG) Indian Island located in Puget Sound, Washington. Construction activities include replacement of structural concrete and steel piles through impact and vibratory driving.  The proposed regulations would set forth the permissible methods of taking, means of effecting the least practicable adverse impact on the affected species or stocks and their habitats, and if applicable, on their availability for taking for subsistence uses (i.e., mitigation); and requirements pertaining to the monitoring and reporting of such taking. LOAs issued under the regulations would authorize the take of marine mammals incidental to the specified activities for a five-year period.