We eventually ended up playing the dry line bulge in north-central South Dakota. We were rewarded with a series of amazing storms, and did make it to the area in time to catch up to a long-lived cyclic supercell, repetively producing tornadoes. We caught up to the storm in one of its last cycles before the whole area erupted into a line.
The storm had a monstrous hook and the picture shows a wedge tornado about 20 miles southwest of Aberdeen, South Dakota. As we dropped south away from this storm, in the dusk, we outraced the lowering and the shelf that hung out east-southeastward from it. We could see it hanging like the lip of a mother-ship spacecraft over the road to our west (right), with a suspicious underhang directly over us (which did not become a tornado).
We dropped south to O'Neill, Nebraska for the night.
