151029-M-DF987-509 LAKE TAHOE, Calif (Oct. 29, 2015) A U.S. Marine Corps MV-22B Osprey aircraft from Marine Medium Tiltrotor Squadron (VMM) 163, Marine Aircraft Group 16, 3d Marine Aircraft Wing (3d MAW), flies during Mountain Exercise (MTNEX) 6-15 over South Lake Tahoe, Calif., Oct. 29, 2015. VMM-163 participated in MTNEX 6-15 to develop the squadron's expeditionary proficiency in a dynamic high altitude, cold weather training environment. (U.S. Marine Corps photo by Cpl. Allison J. Herman/Released)