Located near scenic Philadelphia and convenient to New York City, Baltimore and Washington D.C., Naval Air Station Joint Reserve Base (NAS JRB) Willow Grove, Pennsylvania is home to Marine Aircraft Group (MAG) 49 Headquarters. This MAG Headquarters takes great pride in supporting our squadrons that stretch from the Gulf Coast, across the Eastern Seaboard and to the Hudson River. Manned by 150 U.S. Marines Corps Reserve and Active Duty personnel, the MAG-49 units at Willow Grove are part of the 2000 Marines at seven MAG-49 sites and the 39,600 U.S. Marines Corps Reservists training throughout the United States and participating in real-world operations globally.