They were already way off a direct line by going to Offutt the day before (to get around weather), and needed another fuel/weather/overnight stop on the way to KSC. This really was pretty much on a direct line once they'd gone to Omaha!
Just to piggy back/ellaborate on what Paul said, The flight left Edwards on Sunday and flew to Amarillo for fuel and then northeast to Offutt in Nebraska due to wx. On Monday they flew from Offutt to Fort Campbell. Here are the threads covering all this: