The Five Star DEF Story: Got DEF?

On day three of the trip, about 1000 miles from home, I did a system check and discovered the Exhaust Fluid level was under 1⁄2 full. This caught us by surprise, and was somewhat of a concern, since we were traveling off the highways and we had not seen DEF by the bottle at any of the fuel stations in rural Idaho or Montana. We stopped in Spearfish, South Dakota and located a Ford Dealer, hoping to buy Motorcraft DEF by the bottle. The parts department was closed, so we could not purchase any DEF, and the manager advised us that the nearest DEF was in Rapid City, at a Pilot/Flying J Truck Stop...