I'd suggest taking Highway 2 through the Sandhills of Nebraska- a very scenic drive. Camp at Halsey National Forest or Victoria Springs State Recreation Area. I'd also look into camping at either Chadron State Park and/or Fort Robinson State Park, tho' neither is in the middle of this part of your trip.
Safe travels!
taviking22
Omaha, NE
'06 2500HD Silverado 4X4, Duramax LBZ, Firestone air bags
2008 Tracker Pro Guide V-16 Boat
2012 Jayco Pinnacle 31RLTS