Airmen assigned to the 437th Airlift Wing and 315th AW begin to offload cargo from a C-17 Globemaster III at McEntire Joint National Guard Base, S.C., Nov. 16, 2020. Palmetto Challenge is a global mobilization exercise held at McEntire Joint National Guard Base, S.C. The exercise is held in order to develop readiness and awareness in a simulated deployed environment for over 100 Airmen from Joint Base Charleston.