3rd Marine Littoral Regiment was activated March 3, 2022, on Marine Corps Base Hawaii. 3rd MLR was redesignated from 3rd Marine Regiment and inherited the lineage of that storied regiment. The MLR, as a part of the Stand-in Force, disrupts the adversary in a contested littoral environment through reconnaissance, counter-reconnaissance, and sea denial operations in order to support the maritime campaign. 3rd MLR is a major subordinate element of 3rd Marine Division, III Marine Expeditionary Force.