Activated January 1967 at Santa Ana, Califorrnia,
as Marine Medium Helicopter Squadron 561, and assigned to Marine
Aircraft Group 56, 3d Marine Aircraft Wing, Fleet Marine Force,
Deactivated 27 October 1969
HMM-561 provided refresher training for UH-34 crews deploying
to Vietnam. It was the last operational UH-34 squadron in the
Fleet Marine Force.