Designed to offer mission flexibility, the C-40A is a versatile FAA-certified 737-700 convertible / "combi" aircraft, optimized to transport passengers and cargo around the globe. The aircraft can be configured to carry all-passengers, all-cargo, or a combination of both. The C-40A is part of Boeing's C-40 series of aircraft, which also includes the C-40B and C-40C. The C-40A is currently on offer as the C-40Ai to countries around the world.
What are these planes typically used for?
B737 c-40A clipper
https://www.boeing.com/defense/c-40a/
So next question is "who or what" are they flying from Nevada to Virginia and needing 6 planes to do it?